Benz Patent-Motorwagen

Motorwagen Nr. 1

Benz began work on his vehicle in 1884 but it was in Spring 1885 that he got his prototype moving under its own power for the first time. He worked continually to improve his vehicle. Initially it would only run for a short distance and was driven only in the factory grounds. Over the year 1885 its range grew, and in the latter part of the year Benz took it out on unfrequented roads and at night.

By the end of 1885 Benz was sufficiently confident in it to prepare a patent application. A further factor was progress in litigation which challenged Nicolaus Otto's patent for his four-stroke engine. Benz's patent application was filed on 29 January 1886. and granted on 2 November 1886 (if a patent is granted, the date of the patent is the filing date). This first vehicle is known as Patent-Motorwagen Nr. 1.

As Benz was developing Nr. 1 continuously, by the time patent DRP37435 was submitted, the vehicle was no longer that depicted. Around the end of 1885 or in early 1886, work began to build a new body with wooden wheels and heavier-duty transmission; meanwhile, testing and incremental development of Nr. 1 continued. At some point Nr. 1 was scrapped and the engine and some other parts were transferred into the new vehicle: Nr. 2, the motorised Stanhope gig. Exactly when this happened is not known, nor is the final form of Nr. 1. In 1895 the Sales Manager sought to recreate the final form of Nr. 1, incorporating surviving parts from the original vehicle. The nature of the rebuilt vehicle and the final form of Nr. 1 are discussed in the section Rebuild of Patent-Motorwagen Nr. 1.

Motorwagen Nr. 2

The engraving captioned Patent-Motorwagen Nr. 2 was used by Benz & Cie in advertising in 1888 without any identification as to what it depicted. It appeared in William Worby Beaumont's 1900 book Motor Vehicles and Motors with the caption "Benz second motor tricycle carriage // Made in 1886, and ran at 10 miles an hour maximum". Worby Beaumont states that the image is "from an engraving lent me by Mr. Benz, of the second type of car he made. It differs from the first mainly in the seat or body."

The engraving shows a vehicle which looks like a motorised Stanhope gig. The rear half of the vehicle is similar to the surviving Patent-Motorwagen in the Science Museum in London. It has:

• the same type of seat and controls: hand levers on stalks in the middle and a lever outside the frame tube on the left;
• two vertical cylinders (silencer and carburettor) to the left of the sprocket of the rear wheel;
• a horizontal flywheel at the back which barely projects behind the rear wheel.

These tie this vehicle to the vehicle in the Science Museum and distinguish it from the vehicle in the patent drawings DRP37435. But it was not a completely new vehicle: the efforts in 1895 to recover parts of the original vehicle from what had been salvaged in 1887 imply that the engine and transmission from Nr. 1 were largely carried over into Nr. 2.

On 4 June 1886 a report appeared in the Neue Badische Landeszeitung which describes a motorised tricycle, including that

In front of [the seat] are the steering and brake levers. By means of another lever, the vehicle is set in motion or stopped at will, by directing the belt, which transmits the motive power of the engine to the wheels, onto the loose or fixed pulley.

This describes the levers in Model 2 and is mostly correct about what they did (the hand lever beneath the steering controlled the clutch which engaged low gear).

Another report appeared in the Neue Badische Landeszeitung of 3 July 1886. Mercedes-Benz's Chronicle 1883 – 1900 records this as First public outing of Carl Benz with a heavily retouched photograph of Carl Benz driving Nr. 2 with Max Rose, director of Benz & Cie, beside him.

The combination of Benz's statement to Worby Beaumont that the engraving is of his second motor tricycle with the detail about the levers in front of the seat and the photograph of Benz driving Nr. 2 with Max Rose beside him combine to establish that:

• the engraving shows the vehicle which Benz drove around Mannheim in early summer 1886;
• it was Benz's second type of car, hence Patent-Motorwagen Nr. 2;
• Patent-Motorwagen Nr. 2 was the first practical car, not Patent-Motorwagen Nr. 1.

Motorwagen Nr. 2 was far better suited to use on public roads than Nr. 1: it had two gears and better brakes; all the controls could be reached by the driver; it was less top-heavy and had stronger, wooden wheels with iron tyres.

Motorwagen Nr. 3

Two photographs exist showing side and rear views of a vehicle which is intermediate between Nr. 2 and the Science Museum's vehicle. Nr. 2 had a single seat and no suspension at the front. The photograph of the side shows a vehicle very similar to the Science Museum's, with a front rear-facing seat and full suspension, i.e. a calèche. The photograph of the rear reveals signs of welding which suggest that it has been modified from some previous form. The engine is consistent with that depicted in Nr. 2.

In the records of Benz & Cie, there is a Patent-Motorwagen Nr. 3. Nr. 3 is usually identified as the vehicle in a contemporary newspaper illustration in which Benz and his wife Bertha are depicted driving around Munich in September 1888. This vehicle looks very similar to its prototype: the differences lie at the back, where the engine of the prototype is not enclosed behind the seat.

Nr. 1 and Nr. 2 are stages in the development of the Patent-Motorwagen. Nr. 3 is used here for the final stage in this development. Benz appears to have used it as his personal car until switching to a new Model 2 around the end of 1887. Around this time, Nr. 3 was scrapped ("disassembled"). Parts which could be reused were salvaged.

Model 2

Benz made his first sale of a motor vehicle in 1887 to Émile Roger, a bicycle manufacturer who went on to become his French agent for motor cars. This sale seems to have been semi-private: Roger came to see Benz in Mannheim and Mercedes-Benz date public sale (and therefore production) as having started in 1888. In September 1888 Benz exhibited a vehicle in Munich and was pictured in a newspaper driving around Munich with his wife Bertha. The vehicle in that image matches exactly the Science Museum's and (slightly less well) the photograph used here with the caption Patent-Motorwagen Model 2. It too has a horizontal flywheel which projects slightly behind the rear box. This photograph is Fig. 27 of Benz's Lebensfahrt, a combined memoir and technical history published in 1925. Its caption translates as

My first production car from 1888. 1.5 hp, 2 speeds up to approximately 16 km/h, price at the time 3000 Marks

That the vehicle with the rectangular wooden box over the engine and the horizontal flywheel was the first production car is confirmed by an advertisement of unknown date which appeared in Britain with the caption "The first petrol motor car".

Worby Beaumont does not depict this vehicle: his next image is that shown here as Patent-Motorwagen Model 3. In it, the body was changed to emphasise the passenger-carrying part and semi-circular ribs were added to the sides of a smaller rear box. They were the external face of two water tanks / radiators which were added to the coolant system. Given the visible changes to the body, the vehicles with a single large wooden box are identified here as Model 2, while those with ribs are Model 3.

Model 3

The image used here of Model 3 is that in Worby Beaumont. He captions it "Benz third motor carriage // Made in 1888, for running at 12–15 miles an hour". The image is derived from a photograph taken outside the works in Mannheim. The photograph is sufficiently clear to be able to see the vehicle's horizontal flywheel. In his Lebensfahrt, Benz tells a story of selling an 1888 car to a schoolmistress from Hungary. Circumstances suggest that this may have been the first Model 3 with a horizontal flywheel, implying that it was produced in 1888.

The initial changes from Model 2 were mainly to the form of the body. However, Bertha Benz's trip in a Model 2 to Pforzheim in August 1888 highlighted problems going up hills. This prompted the use of a larger engine and the addition of a second belt-system in place of the reduction gearbox; the flywheel was changed from horizontal to vertical. As no vehicles survive between the Model 2 in the Science Museum in London and Eugen Zardetti's Model 3 of 1893, there is no information about what exactly happened and when. What can be said is that the engine of Zardetti's Model 3 resembles that of the Velo of 1894 and a smaller version of the Vis-à-vis of 1893.

Given the scale of the changes to the engine, it seems unlikely that the two-belt Model 3 was produced before 1890. As sales before 1890 appear to have been made only by Émile Roger in Paris, he would have dictated what was produced. The existence of a print of 1890 of an apparently Parisian scene with a Model 2 suggests that Roger continued to sell the Model 2.

In 1890 Friedrich von Fischer and Julius Gauss replaced Max Rose and Friedrich Esslinger as directors of Benz & Cie. This allowed Benz to spend more time and money developing his vehicle; a professional sales operation was introduced to complement Roger's activities in France. Sales of the two-belt Model 3 may have begun in 1890 but outside France are unlikely to have been before 1891.

Rebuild of Motorwagen Nr. 1

Around 1895 the Sales Manager at Benz had surviving parts of the original vehicle sought out with a view to recreating its first form, the motorised velocipede. The reconstructed vehicle was photographed in the late 1890s. In 1906 it was given to the Deutsches Museum in Munich. In 1925 it headed a procession of historic vehicles with Benz at the controls. A video from the 1920s or 1930s shows it being demonstrated. It remains in the Museum today.

The original vehicle appears to have been rebodied twice. It seems likely that the motorised velocipede was developed further after the drawings for patent DRP37435 had been prepared and that the 1895 rebuild was based on its final form before it was given a new body as Nr. 2.

The 1895 rebuild provides evidence as to the final form which Nr. 1 took. But it is not an accurate copy. Its carburettor is from the Benz Velo and it uses a crossed drive belt, which appears to have been introduced with the two-belt Model 3. A sight gauge has been added to the carburettor, as in the 1880s, but it is not positioned as in the 1880s.

Other changes may have been made to make the vehicle easier and safer to drive. The platform in patent DRP37435 is 80cm above the ground; in the rebuild it is 60cm. Benz's expenditure on his private project was severely constrained. As his aim was a true horseless carriage, it seems unlikely that he would have given the motorised velocipede a new frame first.

Replicas of the rebuilt vehicle have been produced from the mid-twentieth century. About 150 examples from various suppliers have been made. In 2001, Daimler (now Mercedes-Benz Group) began manufacturing replicas by hand. They can run on petrol but are not permitted on public roads.

Conclusion

The Patent-Motorwagen has been recognised as the first practical automobile (Nr. 2) and the first to enter production (Model 2). As its creator, Carl Benz has been hailed as the father and inventor of the automobile.

Development and specifications

In 1873 Benz developed a successful town-gas-powered two-stroke piston engine. He was less successful in running a company and in 1883 was supported to found a new company with solid finances but in which he held only a 5% shareholding. He was already working on a four-stroke engine and on using vaporised hydrocarbon fuels instead of town gas. His dream remained, to employ a gas engine to power a horseless carriage.

Benz started work on his Motorwagen in 1884 in his own time, outside his responsibilities as a director of the company. He continually made changes to it, so it is hard to tie down details of its specification at any particular date. What can be said is that the first version which Benz was happy to take into Mannheim and be seen in was the Patent-Motorwagen Nr. 2 in summer 1886. This was his first practical car: it fixed the greatest inadequacies in the design of Nr. 1 and was sufficiently reliable not to have to worry about constant breakdowns.

The Benz Patent-Motorwagen was a motor tricycle with a rear-mounted engine. The vehicle contained many new inventions. It had a frame of steel tubing with a floor of wooden slats. The steel-spoked wheels and solid rubber tyres in Nr. 1 were replaced with wooden wheels in Nr. 2.

Steering and Suspension

Steering was by way of a pinion acting on a toothed rack that pivoted the front wheel. In Nr. 1 the stalk to control the steering was at the right edge and the rod to the front wheel ran above the floor. In Nr. 2 it was moved to the centre, just in front of the counter-shaft. In the longer-wheelbase Nr. 3 and the production versions, it was moved further forward.

Elliptic springs were used at the back along with a beam axle and chain drive on both sides. The front wheel in Nr. 1 and Nr. 2 was unsprung; elliptic springs were added in Nr. 3 (1887) and used in all production models.

The quality of the ride was a function not only of the springs but also of the wheels, which were wooden, with thin felloes and (as regards the rear wheels) of large diameter. At the speed which the Patent Motorwagen went, its wooden wheels flexed as they turned, providing a ride comparable to that of the equivalent horse-drawn carriage.

Transmission and Brakes

In Nr. 1, a belt system served as a single-speed transmission, varying torque between a drive pulley and a two-part pulley on a counter-shaft (see the plan of the front of Nr. 1 above). As the drive/brake lever was moved forward from its central position, the fork J shifted the belt from the loose pulley on the counter-shaft E to the fixed pulley F; this is similar to lifting the clutch pedal with a manual gearbox. As the drive/brake lever was moved back from its central position, the spindle L applied a steel band brake to the brake pulley, which was cast with the fixed pulley F (see the view of the underside of the rebuilt original vehicle, although it merges spindle L with rod G).

From Nr. 2, a gearbox was added to the single belt-system to provide a low gear for climbing hills. This was engaged by moving a hand lever beneath the steering control when the belt was on the loose pulley 31 (Fig. V of patent CH960A). Fixed to the loose pulley was sprocket 33 which drove sprocket 35 through reduction gearing on auxiliary shaft 41. When the hand lever on stalk 39 was moved, it engaged the clutch 36 to connect sprocket 35 to fixed pulley 34 and so drive the counter-shaft 22 at reduced speed.

Regardless of how the counter-shaft was driven, a differential inside the pair of fixed and loose pulleys 31 and 34 ensured that the wheels went at the correct speeds when cornering. Chains on each side provided the final drive from the counter-shaft to the rear wheels. There was no reverse.

Model 3 started as a single-belt vehicle with the flywheel horizontal. Later, a second belt-system was added, replacing the reduction gearbox. The low-speed belt system was added to the right of the existing one (see the image of the Vis-à-vis of 1893), with separate hand levers to control whether that belt was driving the vehicle or not.

When the second belt-system was added, the flywheel was switched from horizontal to vertical, eliminating the bevel gears between crankshaft and driveshaft. Worby Beaumont provides details of how the twin belt-drive system worked in the "Ideal" of 1898–99.

As the belts on all twin-belt vehicles are crossed but there is no evidence of crossing on the single-belt vehicles (Figs I and II of patent CH960A show straight belts and the belt is straight in the surviving Model 2), crossing appears to date from the introduction of the second belt-system. It may have been part of the response to slipping of the belt, which seems most likely to have been the reason why Bertha needed to get out and push on her journey to Pforzheim.

The brake in Nr. 1 was a band brake on a brake pulley on the counter-shaft. In Nr. 2 and subsequent versions this was replaced by wooden block brakes on the iron tyres of the rear wheels. The band brake of Nr. 1 could not be retained because the clutch of the reduction gearbox on Nr. 2 lay where the brake pulley had been.

In all versions of the Patent-Motorwagen, when the lever on the left was moved back beyond the centre-point, it applied the brakes. The performance of early brakes was poor: on Bertha's trip to Pforzheim on a Model 2, the passengers had to get out and walk down hills. She repeatedly bought leather which she fixed to the brakes when it wore through.

Braking must have remained poor on the Patent-Motorwagen: in 1898 Zardetti added to his Model 3 a hand-wheel which applied a band brake on the counter-shaft.; in 1958 Caunter added a pedal to the Science Museum's Model 2 which did the same thing. Around 1896 Benz provided a better solution on the Velo: he added a pedal which applied band brakes to drums fixed to the rear wheel sprockets.

Carburettor and Exhaust System

The patent drawings for Nr. 1 show a vertical cylinder beneath the seat in front of the engine. A schematic cross-section shows it to have comprised the fuel tank sitting on the carburettor.

Early carburettors such as Benz's held the fuel in a vessel which was heated by exhaust gases to promote evaporation and counter the cooling which evaporation causes. The liquid surface was disturbed by vibration of the engine and movement of the vehicle and vaporisation of the fuel was increased further either by bubbling air through it or by directing jets of air across it. These methods created fine spray at the surface without the need to pass the fuel through a nozzle, which required pressure and might clog. Such carburettors were known as surface carburettors.

In Benz's first carburettors (to 1890) the vaporising vessel was open at the bottom (below the level of the fuel) and sat within a larger vessel to which air was admitted. By reducing the width of the annulus between them lower down, Benz forced the speed of the air flow to increase, generating small bubbles which moved fast and created the desired fine spray at the surface.

These carburettors had a sight gauge beside them in which the level of fuel in the vessel could be seen. This was needed because the level was not maintained automatically. Instead, the flow rate of fuel had to be managed to match consumption in the engine. In the carburettor shown in patent DRP37435, once cock 8 has been opened, fuel flows under gravity until the cock is closed again: flow continues even if the engine stops.

Patent CH970 shows a mechanism to address this: it sends a fixed (but adjustable) amount of fuel to the carburettor for each revolution of the engine. The flow rate still had to be adjusted manually, but it was a first step towards maintaining a stable level of fuel in the carburettor. The Science Museum's Model 2 has a hollow plug valve dispensing fuel which is rotated slowly by the engine.

The second schematic shows the carburettor from patent CH970. This matches the cross-section of the carburettor in Worby Beaumont's Motor Vehicles and Motors, which he took from the British patent 5789 of 28 April 1886 for Nr. 1. In it, exhaust enters vertically through the centre of the base of the carburettor. This configuration is shown on the engraving of Nr. 2 with Max Rose sitting beside Carl Benz, which Mercedes-Benz use to illustrate Benz's trip round Mannhein on 3 July 1886. The radially-cut discs in this carburettor were the subject of patent DRP43638 of 8 April 1887.

The engraving of Nr. 2 without any passengers shows a very similar pair of vertical cylinders between the left rear wheel and the engine, but the pipe from the bottom of cylinder A goes into the side of the base of cylinder B. The Model 2 in the Science Museum in London has a pair of vertical cylinders which match those in the engraving of Nr. 2 with Max Rose, so that arrangement appears to be later and to have remained in use until about 1890.

In the Science Museum's Model 2, cylinder A is rusty: evidently it has run hot and is the silencer, while cylinder B is the carburettor. This corroborates the identification of the cylinders in images of Nr. 2 and Nr. 3, where examination of the original vehicle is not possible.

The float appears to have been introduced around 1890. Fig.11 of Benz's Lebensfahrt is a schematic cross-section of a Benz surface carburettor with a float. A vertical cylinder has a rounded top with an air intake, the pipe carrying the air/vapour mix to the engine and (in this case) the pipe carrying fuel, to which the float is attached. As the fuel level falls, the float falls and, with it, the rod above. This acts directly as a valve to admit fuel and then to stop the flow as the float rises again. In this carburettor there is no indication from the outside as to the level of fuel inside.

By 1893 Benz had incorporated a conventional float valve in his carburettor. It manifests itself in where the fuel line enters the carburettor: below the level of the fuel. For the siphon to work, the fuel line must be full of fuel. Benz's implementation of the float valve fixed the float to a rod which projects through a boss on the top of the carburettor. This rises and falls with the level of fuel and provides a direct read-out of the level of fuel inside.

The position of entry of the fuel to the float-valve carburettor changed at least once: from the centre of the base in 1893 to the side immediately above the false bottom in the 1895 rebuild (see image in the section Rebuild of the original vehicle). In the carburettor shown in Fig 11 of Benz's Lebensfahrt, air was delivered below the level of the fuel, as it had been in all Benz's carburettors to that date. In the carburettor used on the Velo of 1896 – 99 (which matches that in the 1895 rebuild), the air was directed across the surface of the fuel.

With all the carburettors there was a mixing valve on the intake line. The driver could reduce the richness of the air/vapour mixture from the carburettor by mixing it with additional air. In Nr. 2 the carburetted air rose in pipe C on its way to the intake valve. The knob D is in a similar position to that in the rebuilt original vehicle and its replicas which controlled this.

From Nr. 3 onwards, the mixer valve was controlled by a pointer which was moved across a sector at the bottom left of the seat box. The richness of the fuel/air mixture continued to be controlled in this way until a throttle knob was added c.1895.

On the evidence of the Science Museum's Model 2, the outer vessel of carburettors were steel in the 1880s (it is better able to handle thermal stress from exhaust). The patents indicate that the internal vessel was always copper.

Coolant system

The patent drawings show a form of radiator above the cylinder with flow into it from what is now the drip-oil lubrication port at the top rear of the cylinder. The return flow is shown into the underside of the cylinder, near the cylinder head.

The radiator shown would have held a small volume of water and it had a hole (a on the left half of the diagram) at the top for steam to escape. Early radiators, including all Benz radiators before 1900 used "evaporative cooling": this meant that cooling was primarily by the extraction of the latent heat of vaporisation of water as it boils. In his 1894 journey in a Benz Viktoria (3 hp engine), Theodor von Liebieg recorded water consumption up to 150 litres / 100 km = 2 mpg (fuel consumption was a more modest 21 litres / 100 km = 14 mpg). Boiling of the coolant water would have limited the distance Nr. 1 could travel before more water needed to be added.

The photo of the rear of Nr. 3 shows a small coolant tank above the cylinder with a neck. Its volume was greater than that of Nr. 1's radiator. Through successive iterations of Patent-Motorwagen, the volume of coolant water increased. Model 2's coolant water tank was larger than Nr. 2's and as water boiled away, it was replaced by cold water from a tank beneath the seat. In Model 3, Benz added two substantial copper water tanks/radiators, one at each side of the engine. These are connected to the vessel above the cylinder. After 1895 a condenser (designed and patented by Émile Roger) was added, to reduce water consumption (a schematic cross-section is at Fig.13 of Benz's Lebensfahrt). Despite this, Worby Beamont comments:

On starting the motor, the tanks [labeled] W will be nearly full. . . After the motor has been working for a short time, the water in the jackets and the vessel [immediately above the cylinder] will begin to boil. . . This action will continue until a considerable part of the water is boiled away, when the tanks W must be refilled.

Wilhelm Maybach essentially solved this problem with his patents from 1897 onwards.

The patent drawings for Nr. 1 show two ports to the water jacket for the coolant system: on the top at the end remote from the cylinder head; and on the bottom next to the cylinder head. A new hole on the top of the cylinder would have been required when the first coolant water tank replaced the radiator in the patent drawings. There are signs that it wasn't part of the casting; other changes also appear to have been made to the cylinder in the transition from Nr. 1 to Nr. 2 (see the section Rebuild of the original vehicle).

Bore and Stroke

The bore x stroke of the cylinder in the vehicle in the Deutsches Museum is 90 x 150. It seems likely that this cylinder, cylinder head and cylinder extension are indeed the ones salvaged from the original vehicle in 1887 and subsequently used in a stationary engine.

Their appearance today suggests, however, that they were modified during the development of the original vehicle. The cylinder is similar to that in the patent drawings but the flanges between the cylinder and the cylinder extension are wider and twice as high as those between the cylinder and the cylinder head. On the patent drawings both sets of flanges are the same size (as would be expected) and their width and height match those between the cylinder and cylinder head. This suggests that those flanges (and therefore the adjacent components) are original while the other flanges are later.

The cranks and the end of the cylinder extension today match those on the photograph from 1887 of the rear of Nr. 3. Any change to the cylinder must therefore have been made before 1887. The most likely occasion is in the transition from Nr. 1 to Nr. 2, when the vehicle was rebuilt as a motorised Stanhope gig (which was heavier) and to compensate for the change of the crankshaft:driveshaft ratio from 2:1 to 1:1 Another change which may have been made at this time was to switch from separate piston and connecting rods (as in Benz's stationary engines) to a connecting rod alone.

The "cut-out" for the motion of the connecting rod on the patent drawing is smaller than that in the rebuilt original vehicle (and its replicas). The only reasons to increase the "cut-out" are for larger cranks or to increase the stroke. At 1.67, the stroke / bore ratio is high: surviving examples of Models 2 and 3 have ratios between 1 and 1.39. Model 2 was the next cylinder Benz made; in its earliest version, the cylinder was square, with bore and stroke of 11 cm. He is unlikely to have done this unless he preferred it (later cylinders in the Viktoria were 130 x 130 and 150 x 150). The implication is that Benz's original cylinder (in Nr. 1) was also square, with bore and stroke of 9 cm.

Oswald records three bore / stroke combinations for Models 2 and 3: 110 x 110; 115 x 160; and 130 x 150. It seems likely that 115 x 160 was achieved by boring out the 110 x 110 casting a bit more and increasing the stroke. This increased the power of the engine from 1.5 hp to 2.5 hp, possibly in response to Bertha's difficulties going up hills on her trip to Pforzheim. The Science Museum's Model 2 has this 115 x 160 engine.

Assessment

The engine of the rebuilt original vehicle is a four-stroke engine with trembler coil ignition. When tested, it produced 0.68 PS (500 W; 2⁄3 hp) at 250 rpm, although later tests by the University of Mannheim showed it to be capable of 0.91 PS (670 W; 0.9 hp) at 400 rpm. These details are shown in the Infobox. Technical details of the Model 2 and Model 3 are shown immediately before the section Patent-Motorwagen Model 2.

It was an extremely light engine for the period, weighing about 100 kg (220 lb). Although its cylinder extension and drip oiling system are alien to a modern mechanic, its use of a pushrod-operated poppet valve for exhaust is quite familiar. A large flywheel (horizontal until changed to vertical for the twin-belt Model 3) stabilized the single-cylinder engine's power output.

Patent-Motorwagen Nr. 1

Motorwagen Nr. 1 is identified with the year 1885. During that year, Benz demonstrated it to the public for the first time, in the factory grounds. The vehicle was difficult to control and it collided with a wall.

Later, he took it out onto the public road, but suffered frequent mishaps:

. . . suddenly disaster strikes – in the form of the first "breakdown." The carriage slows down, and ... comes to a complete stop. The driver gets out, kneels down, tinkers, and patches it up. People gather, smiling and laughing. . . Wherever a treacherous fault was lurking, I didn't rest until it was discovered and eradicated. More and more often, the return journey was also made in motorised fashion, that is, without the assistance of people pushing or horses and cows pulling. At the same time, the driving distance had increased from 100 meters to a kilometre or more.

By the end of that year, Benz and his wife had become sufficiently confident that the vehicle would be of practical utility to prepare a patent application. This was submitted on 29 January 1886. The patent is the best available evidence of the state of the Motorwagen at the end of 1885 but the 1895 rebuild suggests that it does not show its final form.

The drawings show a motorised tricycle with wire wheels and a single-cylinder horizontal engine mounted fore-and-aft with cranks driving a horizontal flywheel, almost half of which projects behind the back of the rear wheels. The flywheel had a deep groove which "was intended to accommodate the narrow [leather] drive belt" to a dynamo to provide the current to an ignition coil to generate the spark. Benz' soon abandoned the dynamo for a battery because "on bumpy roads the light pantograph brushes were so shaken that they temporarily interrupted the ignition current", but the groove remained a feature of all horizontal flywheels used.

Apart from the piston cylinder, cylinder extension, cranks and the flywheel, the only equipment which the patent drawings show in the engine is a vertical cylinder in front of, and with a pipe to, the combustion chamber. This lay beneath the seat with its top at the level of the vehicle's floor. The patent drawings provide a section, which was reproduced in Benz's Lebensfahrt: as Fig. 9. It contains the surface carburettor, which typically would have held 1 litre of fuel, with a 3-litre fuel tank over it.

The patent drawings provide a cross-section of the vertical cylinder. This shows the fuel tank sitting above the carburettor, through the base of which exhaust passes, heating the fuel and helping it to vaporise. There was a slide mixer valve on the pipe from the carburettor to the cylinder to adjust the richness of the air/fuel mixture. As the slide was moved in or out (probably by a lever), the air intake holes were covered or uncovered. No other exhaust processing is shown.

The patent drawings do not show an electrical system, but it is discussed in Benz's Lebensfahrt and illustrated in Fig 8. The patent drawings show what looks like the end of a (presumably wooden) box beneath the seat. Given its proximity to the cylinder head, it may have contained the battery and the coil for the ignition.

Drive was taken from the axis of the flywheel through bevel gears on the left side to a pulley, from which a belt ran straight (not crossed) to a pulley on the counter-shaft just in front of the rear wheels. This pulley is in two parts: one fixed to the counter-shaft; the other loose. By means of a lever (9 on Fig. 1 of the patent drawings) at the left of the vehicle, the rod 10 could be shifted to left or right, moving guide pins to transfer the belt from the loose pulley to the pulley fixed to the counter-shaft. Its effect was similar to that of putting an automatic car into Drive. The lever 9 could also be moved back, which applied a band brake to a brake pulley cast with the fixed pulley (see the image of the underside of the rebuilt original vehicle).

The split pulley contained the differential, which ensured that the rotation of the counter-shafts on each side adjusted correctly when turning corners. Final drive was taken by roller chains between sprockets on the partial counter-shafts to sprockets connected to the wheels, which rotated freely on the rear axle.

Steering was controlled by a hand lever at the top of a stalk which was at the right edge of the vehicle, above the counter-shaft. At its bottom was a pinion which acted on a rack at the end of a rod, which ran diagonally immediately above the floor of the vehicle to a lever connected to the front wheel.

The engine was started by vigorously turning the flywheel. There was a step on the left side to ease getting into the vehicle: the floor was 800mm off the ground.

The controls – steering and drive/brake – both by hand, were at opposite edges of the vehicle, 1m apart. Benz talks about being accompanied on his nightly excursions (it eased pushing the vehicle back to the works when it broke down irretrievably), so the apparently bizarre location of the steering may have been motivated by the ease with which it could be operated when the vehicle was being pushed and in the expectation that the vehicle would be controlled by a crew of two.

The seat consisted of a sprung squab for two people on large scroll springs which projected far in front of and behind the seat, hindering access to it. The arm rest and seat back appear to have been of wrought-iron.

Patent Drawings CH960A

There is a second set of patent drawings, CH960A, which shed light on Benz's development of the Patent-Motorwagen. They show a vehicle which has moved on from Nr. 1:

• the wheels are wooden rather than wire;
• the engine has been moved forward so that the flywheel hardly projects behind the rear wheel;
• all the controls can be reached by a driver sitting on the left.

It appears to be intermediate between Nr. 2 and Nr. 3:

• its wheelbase is that of Nr. 2: Nr. 3's was longer, allowing for a larger rear-facing front seat and more space between the seats;
• the drawings are ambivalent as to whether there is front suspension (Fig. II) or not (Fig. I);
• in Fig I (no front suspension), the only possible springing for the seats are the scroll supports, which copy Nr. 2 and were presumably spring steel.

Despite this, there are some features of Fig. I which suggest that it, at least, is from between Nr. 1 and Nr. 2. It shows metal frames for the arm rests and the back of the seat, as on the 1895 rebuild, rather than the wooden seat used in Nr. 2. There is a single stalk for the steering (as on patent DRP37435 and the 1895 rebuild) without a second stalk for the clutch of the reduction gearbox, which is not shown at all (although it is on Fig. III). The supports for the seat match those in Nr. 2. As seat within a wooden box is shown in all images of Nr. 2, this suggests that Fig. I antedates those images, i.e. it was drawn after the drawings of patent DRP37435 had been prepared (late 1885) and before the first public outing of Nr. 2 (early summer 1886).

Fig. I has a scale, which indicates that the rear wheels were to be 1400mm diameter, compared to the 1260mm of Nr. 2 and subsequent Patent-Motorwagen. The cylinder of the engine, the cylinder head and the cylinder extension were to be new, with the bore probably 110mm.

Patent CH960A contains cross-sectional drawings and explanations of how the vehicle worked. This patent, and a parallel one for the carburettor, CH970A, inform the description and analysis of Nr. 2 and subsequent Patent-Motorwagen.

The other pages of patent drawings for CH960A are:

• Fig III: side view of controls and counter-shaft
• Figs IV and V: section and plan of transmission at counter-shaft
• Figs VI – VIII: side, rear and top views of the steering

The patent application CH970A for the carburettor shows exhaust entering the centre of the base. It does this on the engraving of Nr. 2 with Max Rose sitting beside Carl Benz, on Nr.3 and on the Science Museum's Model 2. On the Worby Beaumont engraving of Nr. 2, exhaust enters the side of the false bottom of the carburettor. It does this in DRP37435, which suggests that the Worby Beaumont engraving of Nr. 2 is earlier than that showing Max Rose next to Carl Benz.

Patent-Motorwagen Nr. 2

When William Worby Beaumont was preparing his book Motor Vehicles and Motors (1900), he corresponded with Benz. The image here is captioned "Benz Second Motor Tricycle Carriage made in 1886" and is

from an engraving lent me by Mr. Benz, of the second type of car he made. It differs from the first mainly in the seat or body.

That appears to be an understatement. The appearance of the vehicle was transformed: Nr. 1 was a motorised velocipede; Nr. 2 is a motorised Stanhope gig, a light carriage with wooden wheels. With the first, the motor relieves the rider of the effort of propelling the vehicle; with the second, the motor relieves the driver of the cost of maintaining a horse (or hiring cabs).

Nor was this all: a gearbox was added to provide a second, low gear and brakes were added on the wheels. With these changes came an inevitable increase in weight, perhaps from 250 kg to 350 kg. It seems likely that to meet this, the stroke of the engine was increased from 9 cm to 15 cm and the transmission was strengthened (the drive belt and final drive chains were widened).

In early 1886, Benz became more confident about exposing his vehicle to the public. In his Lebensfahrt he writes.

Until then, I had preferred to conduct my test drives far from the city – on the factory grounds or out on the old, lonely ring road that still encircled the city of Mannheim and was hardly ever used – but from the spring of 1886 onward, I no longer shied away from people and their criticism. Now, twilight and darkness were no longer my favourite times for practising and rehearsing. Now I also appeared with my vehicle on the city's streets and squares, even the busiest ones.

A report appeared in the Neue Badische Landeszeitung of 4 June 1886:

For cycling enthusiasts, it should be of great interest to learn that a major advance in this field has been made by a new invention from the local firm Benz & Co. . . .This velocipede is powered by an engine similar in design to gas engines. The engine, with a cylinder bore of 9 cm and placed between the two rear wheels on springs above the wheel axle, represents, despite its small size, approximately one horsepower and makes 300 revolutions per minute, thereby increasing the vehicle's speed to that of an ordinary passenger train. Above the engine, which is powered by a type of gas, ligroin, contained in a reservoir and sufficient for an extended period, is the seat for two people, also mounted on double springs. In front of it are the steering and brake levers. By means of another lever, the vehicle is set in motion or stopped at will, by directing the belt, which transmits the motive power of the engine to the wheels, onto the loose or fixed pulley.

Another report appeared in the Neue Badische Landeszeitung of 3 July 1886. Mercedes-Benz's Chronicle 1883 – 1900 records this as First public outing of Carl Benz with a heavily retouched image of Carl Benz driving Nr. 2 with Max Rose, director of Benz & Cie, beside him.

The photograph of the rear of Nr. 3 (see next section) show that its drive pulley and belt match those in the rebuilt original vehicle rather than the patent drawings, where they were less wide. Given that the changes from Nr. 2 to Nr. 3 appear to have been concerned with adding full suspension and a rear-facing front seat, it seems likely that changes to the engine and the transmission occurred as part of transforming Nr. 1 into Nr. 2. The image of Nr. 2 shows that the bevel gears to the drive pulley were switched to the right between Nr. 1 and Nr. 2 and the crankshaft:driveshaft ratio changed from 2:1 to 1:1 (which added to the requirement for greater torque). Although the rebuilt original vehicle uses a crossed belt (as do all Benz vehicles from 1890), the image does not suggest that the belt was crossed.

When the engine was moved forwards, the carburettor and fuel tank had to be moved. The similarity of the engine seen in the engraving of Nr. 2 to the Science Museum's Model 2 makes it possible to identify the silencer and carburettor as the two vertical cylinders to the left of the rear sprocket. The photograph of the rear of Nr. 3 shows a small-diameter pipe with a cock on it leading from the box under the seat. This indicates that the fuel tank was beneath the seat, the position used in Benz belt-drive vehicles from then on.

As well as the changes to shorten the overhang of the flywheel, the following changes were made from Nr. 1 as depicted in patent DRP37435:

1. the steering control was moved from the right edge to the centre, enabling the driver to control the vehicle from a single position;
2. a second, low gear was added driven from the loose pulley through a sprocket-and-chain "gearbox"; it was engaged using a clutch controlled by a hand lever on a separate stalk next to that for steering;
3. the large lever to the driver's left continued to be dual-purpose: when moved forward from the central position, it moved the belt from the loose to the fixed pulley; when moved backwards, it applied the brakes (now brakes on the wheels);
4. the floor at the front was lowered, curving up to the pivot for the front wheel;
5. the wheels were changed from wire to wood with iron tyres;
6. mudguards were added, both above the rear wheels and, beneath the floor, above the front wheel;
7. lights (important for testing at night) were added;
8. the seat was made more comfortable, with side and lumbar support, padded armrests and a padded seat-back;
9. the scroll springs of the seat were reworked so that they lay beneath the seat and no longer inhibited access to the seat.

Some of these (moving the engine forward, 1, 3 and 9) are in the 1895 rebuild, so were probably made to the motorised velocipede and retained in Nr. 2.

The carburettor seems to have been the part which gave Benz most trouble: he continued to develop it for many years with two further patents, the earlier being submitted in April 1887. Fig. 11 of his Lebensfahrt shows a version with the air intake as a knob at the centre; on the Vis-à-vis of 1893 (and the rebuilt original vehicle), the air intake knob is at one side. The Science Museum's Model 2 has a steel carburettor; copper and brass appear to have been used later.

Patent-Motorwagen Nr. 3

This is the final form of the original vehicle before it was disassembled around the end of 1887. It is known from two photographs: one of the side and one of the rear:

While the side view is clearly related to the Model 2, it is less clear that the rear view is of the same vehicle and that this vehicle is intermediate between Nr. 2 and Model 2.

That the rear view is of a vehicle later than Nr. 2 is evident from the form of the main lever to the left of the seat. On Nr. 1 and Nr. 2 this was a simple lever which was moved back and forth. On the side view and above the left wheel of the rear view can be seen a handle which can be rotated around the axis of the lever. This is present on the Model 2 and its operation is detailed in the drawings for patent CH960: when rotated it moves the rod sideways which shifts the belt between the loose and fixed pulleys.

To the left of the handle and aligned with one of the spokes of the left wheel is a thin rod which disappears behind the (foreshortened) left mudguard. There is nothing on Nr. 1, Nr. 2 or Model 3 which would be that far out from the centre line of the vehicle. Only with the rear-facing double seat of Nr. 3 and Model 2 is there something in that position towards the front of the vehicle: the support to the backrest of the rear-facing seat. The leftmost end of the backrest itself can be seen poking out to the left of the wooden enclosure for the seat.

The side view shows the box beneath the seat stopping there rather than, as in Model 2, extending backwards to enclose the engine. The rear view also does not enclose the engine, so the two views correspond. On the rear view it is evident that the enclosure for the seat projects out sideways beyond the supporting rough timber box. The wooden enclosure for the seat corresponds to that on Nr. 2, where it is supported by metal scrolls from the main tubes. It is as though those supports have been removed and the rough wooden box inserted to support the seat. On the side view it is covered up at the front by three fielded panels and at the side by finished timber, in the manner of Model 2 but not extending back further than the seat.

There remains the question as to whether this is another stage in the evolution of the original vehicle or whether it is a Model 2 with less cladding. That can be settled by considering the size of the engine cylinder and of the coolant water reservoir above it. The size of the engine cylinder matches that in the 1895 rebuild of the original vehicle (as seen in the late nineteenth century photograph in Worby Beaumont).

The coolant water reservoir is taller than it is broad. It also has a neck which projects above the bottom of the wooden enclosure for the seat. Its shape matches that on the photograph of Nr. 2 with Max Rose beside Carl Benz. That on the 1895 rebuild is more squat and lacks the neck. The reservoir on the Model 2 is even broader and again has no neck.

These characteristics establish that these photographs are of a further stage in the evolution of the original vehicle in which the front was rebuilt with a rear-facing seat and transverse full-elliptical springs added to provide full suspension.

The design appears to be based on the calèche, a type of landau with a half-hood at the rear and with the rear-facing seats of less importance than the forward-facing ones. A calèche required a coachman as well as at least one horse, so a motorised calèche would save its owner substantial costs.

On 8 April 1887 Benz applied for a patent for a 2-speed gearbox using epicyclic gears. Nr. 2, Nr. 3 and Model 2, however, used a low gear driven from the loose pulley through sprockets and chains and an auxiliary shaft together with a clutch. Epicyclic gears were not used until the Crypto gear in the late 1890s.

Technical data for Models 2 and 3

The primary source for this table is Oswald's Mercedes-Benz Personenwagen 1886 – 1945. No explanation is given for the three columns for different size of engine. The 1.5 hp of the first column corresponds to the power reported in the caption to Fig. 27 of Benz's Lebensfahrt and may represent the initial size of engine in the Model 2. The size 110 x 110 mm was subsequently used on the Benz Velo.

The cylinder of the Science Museum's Model 2 is 116 x 160 mm. The Museum describes it as 1.5 hp, perhaps because that is what the caption says on Fig. 27 of Benz's Lebensfahrt and the table above was not published until 1986. The caption also says that the vehicle depicted ran at 10 mph whereas, after restoration, C.F.Caunter found that it could run at 14 mph and in 1958 averaged 9 mph on the 56 miles of the London to Brighton run.

The third column most likely relates to the two-belt Patent Motorwagen from 1890. The values are, however, puzzling. Oswald gives 130 x 130 = 1730 cm³ and 3 PS at 450 rpm for the early Viktoria and Vis-à-vis. This is corroborated by two examples in the Schlumpf collection (engine numbers 31 and 55 from 1893; Zardetti's 3-wheeler was number 24). Oswald gives 130 x 150 = 1990 cm³ and 4 PS at 500 rpm for later versions of the Viktoria and Vis-à-vis.

Patent-Motorwagen Model 2

The year 1887 marked the transition for Benz & Cie. from development to production. The model which was sold was a calèche with a 1.5 PS (1.1 kW; 1.5 hp) engine; two speeds from a single belt-drive and a reduction gearbox; and wooden wheels with external brakes on the rear wheels. The engine with the flywheel was covered by a wooden box with a tonneau cover, through which the top of the coolant water tank projected. The back of the box was serpentine in form with a ducktail and consisted of two doors hinged at the sides to provide access to the engine. Optional extras were a folding half-hood and lights.

During the year, Émile Roger, a bicycle manufacturer in Paris who made Benz stationary engines under license, visited Carl Benz in Mannheim and bought a vehicle. Roger became Benz's agent for the Motorwagen and by the time Benz visited him in Paris in March 1888, Roger had sold one to Émile Levassor.

As well as the vehicles sold to Roger in 1887 and through Roger to Levassor in early 1888, there is strong evidence of:

• the vehicle which Benz himself used during 1888, which Bertha took for her trip to Pforzheim in August 1888. This is often referred to as Nr. 3, but seems more likely to have been a Model 2: the concern about the vehicle's inability to climb hills would have been much less if it had been the original vehicle rather than a recently-built Model 2;
• the vehicle which Benz displayed at the Munich exhibition and drove around with Bertha beside him. This appears to have been distinct from the one Bertha had used;
• the vehicle in the photograph at the top of this section. The high-resolution version of this photograph shows that its manufacturer's plate read "E.Roger // No. 3X7", where X could be 4 or 6. The side of its rear box is painted all over and the steps to get into the vehicle take the form of a reversed "S", as in the Munich vehicle;
• the unique surviving example of Model 2 in the Science Museum in London. This bears the manufacturer's plate "E.Roger // No. 367". As in the Munich vehicle, the central panel of its rear box is varnished; unlike it, the steps to get in only have a single curve rather than being a reversed "S". It is therefore not a match for either the Munich vehicle or that in Benz's Lebensfahrt.

There is also:

• an engraving of a Model 2 in a (Parisian?) street scene from 1890. Although this doesn't show much of the engine beneath the rear box, it does show a tensioner on the chain to the rear wheel and a third, large sprocket on the front shaft of the reduction gearbox. Both these are also shown in the drawing of the Munich vehicle.

Apart from finishes and small details, all of these vehicles look the same and are clearly based on Nr. 3. We may infer that the vehicle Roger bought from Benz in 1887 was also a Model 2. It follows that it was in 1887 that Benz's Patent-Motorwagen Model 2 started series production. The presence of E.Roger's manufacturer's plate on a fully-built vehicle in Mannheim suggests that vehicles built for Roger may not have had Mannheim Fabrikationsnummern.

The survival of the example in near-original condition makes it possible to study details of the construction and cross-check them against patent CH960A. This confirms that the belt ran straight (not crossed) and the reduction gearbox in front of the counter-shaft to provide the low gear.

The wheels have alternate inner and outer spokes, as in a bicycle wheel. As was common in large wheels, the felloes are made from two laminas of steam-bent wood rather than from wood which was cut and shaped before being joined. There is a thin iron hoop inside the right-hand rear iron tyre, to which the felloes were bolted as part of its construction. This was permanent and strengthened the wheel while retaining the ease with which the tyre could be replaced.

About 200mm from the axle, the inner spokes are enlarged and bolted to the rear sprocket of the chain drive. This addresses a problem which bedevilled early steam road vehicles: transmitting the torque to the rim of a wooden wheel (wood being required for its flexibility and better ride) without suffering breakages at the nave. The De Dion Bouton steam carriage which completed the 1894 Paris–Rouen race fastest used metal carriers to transmit torque to the heavy felloes. Goldsworthy Gurney had introduced them in his steam drag of 1829.

The front wheel has both the iron tyre (as with the rear wheel) and a solid rubber tyre over it. The rubber tyre provided grip on slippery road surfaces, necessary as it was the sole contact with the road to steer the vehicle.

The top of the coolant water tank projects through the cover over the engine. As cooling of the engine depended on the radiation of heat from this tank, it had to be exposed to ambient air.

Although the version of Model 3 with a horizontal flywheel appears first to have been produced at the end of 1888, it seems likely that Émile Roger was selling the Model 2 at the Paris Expo in 1889 and that series production of Model 2 continued through 1889. In The Birth of the British Motor Car (1982), T.R.Nicholson judged that the number of Patent-Motorwagen made to 1888, including the prototypes, was six.

Bertha Benz's trip to Pforzheim and the exhibition in Munich

Carl's wife Bertha came from a successful business family. Her dowry had enabled Benz to start his business. Her family had put more money into Benz & Cie when it had been in difficulties. She counseled Carl in business matters.

In his Lebensfahrt, Benz sets out the gestation of this trip:

It was the summer of 1888. The schools had closed their gates . . . in the minds of my boys—Eugen was 15, Richard 13—the audacious idea arose to take a newfangled holiday trip and drive out into the world in the car. "But we'll never get Father's permission," Richard lamented, deeply saddened. "Then we'll ask Mother," replied Eugen, "she's more daring than Father and will probably go with us." And so the plot was hatched.

No doubt Bertha saw the advantages of the publicity such a trip would create. She decided that the trip would be to her mother's in Pforzheim, some 50 miles away (60 miles by the route they took there; 50 miles for the return journey).

They set off at the crack of dawn one day in early August 1888. To continue in Benz's words:

Eugen was at the wheel, his mother beside him, and Richard in the small back[-facing] seat. Less than an hour later, they reached Heidelberg on the lovely, level road. Everything went well until Wiesloch, too. But then, as the roads became hilly, the trouble began. The transmission wasn't designed for such steep inclines. Eugen and his mother had to get out and push while Richard steered. Going downhill, his mother felt uneasy. What if the simple wooden brake with its leather covering suddenly failed? Fortunately, this didn't happen on the entire journey. However, new leather pads had to be bought from the village cobblers and nailed on again and again from time to time. The journey continued, but the leisurely drive was over. Since the chains were stretching and slipping off the gears; they stopped in front of a village blacksmith. The villagers arrive and admire the motor car as if it had just fallen from the sky. After the chains had been tightened, they continue on their way—until the next breakdown. The car stalls because the fuel line is blocked. Mother's hatpin is just the right surgical instrument to repair the damage. During another breakdown, when the ignition failed, the "first female long-distance driver" even sacrificed her garter as insulation.

Although Eugen was driving when they set off, and Richard drove when Bertha and Eugen were pushing the car up a hill, Benz describes Bertha as the "first female long-distance driver", so she probably did most of the driving. On the way, they had to stop in Wiesloch, where Bertha bought some Ligroin fuel from a pharmacy.

Bertha was evidently enough of a mechanic to work out why the car had broken down and improvise solutions; she probably did most of the driving. However, it was the boys who came up with the idea of the trip; the use of leather coverings for the wooden brake blocks was an established practice.

Although this trip succeeded in gaining publicity, it made manifest a serious defect in the vehicle (which Benz may have been aware of): its inability to go up hills, despite his having included a second, low gear through the reduction gearbox.

What is evident from the account is how primitive and unreliable the Model 2 was in August 1888, especially when put under pressure. The sales to Émile Roger and Émile Levassor were both to professional manufacturing engineers, who would be as interested in understanding the capabilities of the new technology as in using it as a means of transport. As with steam coaches in Britain in the 1830s, ordinary users would soon tire of breakdowns and revert to the more reliable horse. In Roger's case, it led to his becoming Benz's agent for the Motorwagen in France; in Levassor's it helped him to build his first vehicles using the Daimler licence. Paris appears to have developed early the infrastructure of mechanics who could support owners of motor vehicles and make their ownership a success.

Exhibition in Munich, September 1888

One month later, Benz exhibited his vehicle at an industrial exhibition in Munich. In his Lebensfahrt he describes it as a triumph and his vehicle received a gold medal. He and Bertha drove around Munich to demonstrate the vehicle and their drives were reported in the local Neue Nachrichten on 16 and 18 September 1888. It was reported in the Leipzig Neue Illustrirte Zeitung of 1 December 1888 with the illustration shown. The illustration was reproduced in the Scientific American of 5 January 1889.

But of sales, it produced none.

Patent-Motorwagen Model 3

Single-belt version

Model 3 differs from Model 2 mainly in the appearance of its body. Although almost all Model 3's had a vertical flywheel and two belts, the change from Model 2 to Model 3 was made with the single-belt transmission and the horizontal flywheel. As well as the new body, Model 3 had two large water tanks / radiators to supplement the coolant water tank above the cylinder (which was shrunk and lost its ability to be refilled). The water tanks / radiators were responsible for the distinctive horizontal ribs on the sides of its rear box.

Carl and Bertha were driving a Model 2 around Munich in September 1888, so we may infer that Model 3 was not ready by then. The image here showing Benz and Josef Brecht driving a Model 3 in a Rhineland landscape is based on a photograph of them outside the works in Mannheim. The photograph shows more clearly that this vehicle had a horizontal flywheel and the reduction gearbox in front of the counter-shaft, so a single belt-drive. The main changes to the bodywork were:

• at the front, the rear-facing seat was replaced by a vertical dash or splashboard, immediately behind the elliptic springs;
• at the back, the single wooden box which enclosed the engine and the seat was changed to emphasise the passenger-carrying part with the rear box subservient

An optional extra was a single rear-facing seat, as used by Eugen Zardetti's son on the 1893 photograph of him in his (two-belt-system) Model 3. It was cantilevered out from the front panel, hanging over the front suspension and the front wheel, as can be seen more clearly in the image in the Mercedes-Benz Public Archive.

In his Lebensfahrt, Benz tells the story of selling a car from 1888 to a schoolmistress from Sommerein (now Šamorín in Slovakia). He refers to Eugen (born 1873) delivering it, driving the 50 miles from Vienna. This (and Benz's wording) suggests that the sale took place some years after 1888. A testimonial by Róza Kalocsa from Šamorín in an 1893 Benz brochure describes how well her car runs on level ground. As Benz explains that the teacher couldn't afford one of his cars but did then buy it (with assistance from a colleague), the most plausible explanation is that the single-belt horizontal-flywheel Model 3 was built in 1888 and sold to her in 1892 at a discount.

Benz exhibited at the 1889 Paris Exposition and had a display there which was separate from Roger's. It would appear that he was able to show the single-belt Model 3, while Roger had the Model 2. Benz had "practically no success".

Roger was a much better salesman, and at some time sold the Model 2 which was exported to England. It seems unlikely that he made no sales at the Expo to French customers. In 1893 vehicles were being made to order with a deposit of one third of the price being taken when the order was placed. If (as seems likely) vehicles were made to order, orders placed with Roger at the Expo would have been manufactured through 1889 and into 1890. If Roger was selling the Model 2, that is what Mannheim would have manufactured (and been glad of the sales while it worked out how to get the vehicle to ascend hills).

Twin-belt version

Although Bertha's trip to Pforzheim in August 1888 had succeeded in gaining publicity, it had exposed the vehicle's inability to go up hills, despite its second, low gear.

Two causes may be inferred from the response: insufficient power; and slipping of the belt on the drive pulley. A larger engine was introduced, along with a second belt-system instead of the reduction gearbox for the low gear. The two-belt vehicles used crossed belts rather than straight, so the switch from straight to crossed belts appears also to have been part of the response.

While it would have been apparent why the car couldn't go up hills, it would have been harder to work out how to fix it. Increasing the power of the engine would help, but could exacerbate the problems with slippage of the belt. Increasing the tension in the belt would make it harder to move the belt between the loose and the fixed pulley. The solution adopted involved a substantial redesign of the engine. That alone indicates the seriousness of the problem and the time, effort and cost required to overcome it. It may have increased the other directors' concerns about the direction of the business and their withdrawal in 1890 (see the next section).

It is possible that a larger engine was introduced first, with the horizontal-flywheel. The Science Museum's Model 2 has the 2.5 hp engine rather than the original 1.5 hp. This has the stroke increased from 110 to 160mm and the bore from 110 to 115mm. That could probably have been achieved by boring out the casting more, using a new piston (or piston rings), connecting rod and cranks, i.e. as a stop-gap. The final form of the engine was 130 x 150mm: that would have required a new casting, so part of the changes to add a second belt-system. As Émile Roger was the only person making sales before 1890, he would have dictated which Model was built.

With the addition of a second belt-system, the controls were changed. In Model 2, turning the handle at the top of the main lever on the left moved the belt between the loose and fixed pulleys while a hand lever on a separate stalk next to the steering engaged the clutch for the low gear. With two belts, the handle at the top of the main lever was replaced by two hand levers below the steering, one for each belt.

Zardetti's appears to be the only surviving Model 3. It has the vertical flywheel, as can be seen beneath the rear box in the side-view of it in the Technical Museum in Vienna. An image of the engine of his vehicle shows it to be similar to that of the Velo of 1894. This includes the positioning of the carburettor at the left back of the engine bay and a silencer in the form of a horizontal cylinder running side-to-side beneath the engine cylinder with a small fraction of the exhaust being tapped off on entry in a pipe to the base of the carburettor.

The wheels appear to be of standard wooden construction: in the photograph of Carl Benz and Josef Brecht in a Model 3, the felloes are made from two laminas of bent wood. Later vehicles, e.g. the Vis-à-vis of 1893 have a metal rim to which the spokes are fixed by special-purpose connectors. As can be seen in the meticulously restored Vis-à-vis, the wooden brake blocks on that vehicle had been superseded by brass ones with leather brake pads.

The Pivot Year: 1890

This section is based on the biography of Benz in David Scott-Moncrieff's book Three-pointed Star (1955). A secondary author of the book was St.John Nixon, who had written The Invention of the Automobile (1936). Scott-Moncrieff corrects obvious mistakes in Nixon's book (Nixon refers to the business as a partnership rather than a company, for instance) and so is preferred as a source where the two differ.

In his foreword, Scott-Moncrieff acknowledges the readiness with which Daimler-Benz had given all the assistance asked of them. The story which Scott-Moncrieff tells about the withdrawal of two directors of Benz & Cie in 1890 and their replacement cross-checks against Mercedes-Benz records but adds why the directors withdrew. Scott-Moncrieff's story appears credible and is consistent with Benz's Lebensfahrt (which is elliptical on such matters, and on dates and sales numbers generally). Scott-Moncrieff writes authoritatively, so he (or Nixon) may have had access to the minutes of board meetings of Benz & Cie. Alternatively, they may have picked up what had gone on through the grapevine of the London motoring clubs, of which Julius Gauss had been a member.

At his marriage in July 1872, Benz was working with August Ritter as Benz & Ritter; Mechanische Werkstätte (Mechnical Workshops). Business was insufficient to support both partners, so Benz bought Ritter out using money from his wife's dowry. Benz struggled through the 1870s but was able to spend time developing his first two-stroke gas engine. By the end of 1880, he was beginning to sell this engine and in 1881 the Mannheim commercial register described his business as the Mannheimer Gasmotorenfabrik (Mannheim Gas Engine Factory). A bad contract with an agent for the sale of his engines led ultimately to Benz withdrawing from the business in 1883 and losing the rights to the engine he had developed.

While this decade of work had been commercially unsuccessful, Benz had acquired a reputation as a capable engineer. Max Rose, a Mannheim merchant, now came to his rescue. Along with his colleague, Friedrich Esslinger, he offered to finance a new company, Benz & Cie; Rheinische Gasmotorenfabrik (Rhenish Gas Engine Factory) of Mannheim. Rose made clear that he was not interested in Benz's ideas for developing a horseless carriage, but that, so long as development and manufacture of stationary gas engines took precedence, Benz could, within limits, pursue his dream. Rose and Esslinger took 95% of the shares and subsequently injected further funds, leaving Benz free of financial worries. Benz pursued his dream of a horseless carriage outside working hours: on Sundays, before work in the morning and after work in the evening.

As the stationary engine business began to prosper and Benz's activities with the horseless carriage started to bear fruit, Benz started to push against the limits which Rose had set. His vehicle won medals at exhibitions and plaudits in the press, but sales were scant.

According to Scott-Moncrieff:

In 1889 he exhibited at the World's Fair in Paris, but with practically no success. . . The two co-directors of Benz [Rose and Esslinger] were dissatisfied with the amount of time and money being spent on the development of motor-cars, and they refused to sanction any further expenditure. After some stormy scenes, [in May 1890] the two sceptical directors withdrew and once again, Karl Benz had a remarkable stroke of good fortune. Two men of ability and foresight, F[riedrich] von Fischer and Julius Gauss, offered to support Benz financially. Although the business was still mortgaged to the late directors, good progress was made and Karl Benz was given a free hand in connexion with automobile development, von Fischer supervising the internal administration, and Julius Gauss the sales . . . Julius Gauss proved himself to be a very capable salesman; indeed he appears to have been one of those rare individuals who could sell anything . . . Benz, on the other hand, was essentially an inventor, an engineer and a technician, with but little gifts for administration and none at all for common salesmanship, but with Fischer and Gauss at the helm, the business made sound progress.

Rose and Esslinger were replaced by von Fischer and Gauss at a single board meeting. This was an amicable hand-over from one pair of investor directors to another. At their parting, Rose told Benz that he should concentrate on the stationary gas engines and have nothing more to do with automobiles.

After 1890 the company focused on producing petrol stationary engines, which found a ready market where town gas was not available. Benz was finally able to spend time developing two-wheel steering, getting his first four-wheel vehicle on the road in 1892. At the same time, the market for cars was segmented. Hitherto, the company had produced the 1460mm-wide Patent-Motorwagen, which was priced at 3000 Marks.

The first four-wheeled cars, the Viktoria and the Vis-à-vis, introduced in late 1892 were 1600mm wide and priced from 4000 marks. The Velo, introduced in 1894, was 1250mm wide, used cycle-type wire wheels and cost 2000 marks. The names of these vehicles were descriptive: Viktoria is a type of carriage (named after Queen Victoria), while Velo was a contracted form of the original name, Velociped, one of the German spellings of velocipede. Vis-à-vis is a generic term for carriages with face-to-face seating, while later models before 1900 included Phaeton and Milord.

Sales Numbers

The number of Patent-Motorwagen sold is obscure. One data point is that the Model 3 delivered to Eugen Zardetti in February 1893 was Fabrikationsnummer 24. That may be considered the end of production of the Patent-Motorwagen: the first Viktorias were produced and sold in late 1892, along with the Vis-à-vis. By the end of 1893, the Fabrikationsnummern had increased to 69 and the Viktoria delivered to Theodor von Liebieg by rail in Spring 1894 was number 76. Sales of the Velo are reported to have begun in April 1894 and soon dominated production.

In his Lebensfahrt, Benz hints at how difficult it was to sell his car in the years after 1886. After describing the achievements of 1885 and 1886, he writes:

So I had risen . . . from the first stage of every invention: from thinking, thinking, drawing, and calculating to the second stage, to practical execution and realisation, to action! Now that I thought I was at the height . . . I realized that I was standing . . . at the very bottom, and had to knock like a beggar at the doors of humanity and its culture. . . This was the third and last stage of invention, that dangerous stage at which many a great inventor has collapsed in despair . . . Just one example [of the challenges I faced:] Dr. G. van Muyden, librarian of the Imperial Patent Office in Berlin [wrote in 1889]: "Benz also built a gasoline car, which caused a sensation at the Munich exhibition. This application of the gasoline engine, however, is no more likely to be promising than that of steam to the movement of road carts."

Successive chapters of the Lebensfahrt set out what happened in various countries. The first buyers were from France and the USA. The sale to Émile Roger in 1887 is described and then Roger's sale to Émile Levassor in early 1888 and Roger's appointment as his exclusive agent for sales of his cars in France. He then talks about demand for his cars in France becoming so great that the factory has to be expanded. This did not occur until after 1893, in the years of the Benz Velo. There are no specifics about what happened in the USA; elsewhere there are references to the World's Columbian Exposition in 1893 and to the Chicago Times-Herald Race of 1895, so, again mid-1890s.

At the end of this chapter, Benz talks about England, where sales were suppressed by the Locomotive Acts until 1896. He says that in practice the barriers to sales in Germany were just as high: for many years he made no sales in Germany Later, he talks about his own experiences driving around Germany, where people shouted "witch's cart" at his vehicle. He then says that his first customers had similar experiences, citing one who had bought a Viktoria, so late 1892 at the earliest.

There are then two chapters, about his patented two-wheel steering and handling on country roads, before Benz returns to discussing sales with a chapter titled "The first sales in Germany, Hungary and Bohemia". He perfected his two-wheel steering in 1892 and sold cars with it during that year (one of the testimonials in an 1893 brochure refers to the delivery of a four-seat car in October 1892; the three-wheeled Model 3's had at most three seats). This sequencing of chapters suggests that sales in Germany and Austria-Hungary started around 1892.

Benz starts his chapter about sales in Germany, Hungary and Bohemia with a story about his first sale in Germany being to a man whose father demanded that the transaction be reversed because the buyer was mentally ill. The next buyer wanted a car "before I die", but lived many years. Then comes (without her name) Róza Kalocsa from Sommerein and (with his name) Theodor von Liebieg of Reichenberg (now Liberec), who placed his order on 31 October 1893. This is all consistent with sales in these markets having started around 1892.

The 1893 brochure includes testimonials from 12 people who had bought cars from Benz & Cie, 9 from within post-1871 Germany (including Richard Freudenburg of Süchteln, who later claimed to have bought his car in 1890) and 3 from Austria-Hungary: Julius Jalowetz of Vienna, whose first journey in his car was reported in the Neuen Wiener Abendblatt of 3 November 1892; Béla Hatschek in Budapest, who obtained a permit for his car on 26 November 1892; and Róza Kalocsa. All these testimonials are from between 29 January and 7 February 1893, so before Zardetti's car was delivered to him.

When Zardetti's car was delivered, legend had it that Carl Benz accompanied it and showed Zardetti how to drive. Zardetti's motoring diary records that the car was transported by train to Constance, accompanied by 18-year-old mechanic Matthias Bender, who drove Zardetti to Bregenz and stayed a week, teaching Zardetti a couple of hours a day.

In Mercedes-Benz: Personenwagen 1886-1945 (1985), Werner Oswald, with access to Mercedes-Benz's records, gives statistics of the numbers of vehicles sold by Benz & Cie from 1886 – 1900, broken down by country. However, while data are specified for each individual year after 1893, the data are aggregated for the years 1886 – 1893. Oswald states that about 25 three-wheel Patent-Motorwagen were manufactured (not sold).

In the light of the qualititative history of sales set out above, it is possible to draw up an illustrative disaggregation of Oswald's data by year. The principles which have been used are that sales within each market (except England) rise in arithmetic progression from the year that sales begin; and that the numbers should be consistent with other data (such as the testimonials in the 1893 sales brochure and the number of sales in each market in 1894):

As a rough-and-ready approximation, sales in 1886 – 1889 are identified as being of Model 2 and in 1890 – 1892 as Model 3. Sales in 1893 are considered to be of the Viktoria and Vis-à-vis, while in 1894 the Velo was added. They suggest that Émile Roger sold around 7 Model 2's (including the one to England) and around 24 Model 3's. Benz & Cie's sales were all of Model 3 and were 9 in Germany and 5 elsewhere.

These numbers suggest that Mannheim gave Fabrikationsnummern to vehicles which they were selling but not to those produced for sale by Émile Roger. This is supported by the high-resolution version of Fig 27 of Benz's Lebensfahrt, on which the manufacturer's plate reads E.Roger. That photograph is from the Benz archives, so was presumably taken in Mannheim, not Paris (where the factory burned down in 1896). Roger was reported to have been importing "loose engines" from Mannheim in the mid-1890s. According to T.R.Nicholson, "Roger's operation amounted to no more than assembly and marketing". It seems likely that the 3-wheelers were manufactured completely in Mannheim before being disassembled sufficiently to qualify on entry to France as the import of parts.

Rebuild of Patent-Motorwagen Nr. 1

Around 1895, the Sales Manager at Benz had the parts of the original vehicle sought out with a view to their reassembly. It seems likely that the engine cylinder and associated parts were indeed recovered from the factory, where they had served in a stationary engine. The flywheel may also have been original or part of a batch produced in 1885, before Benz had abandoned a dynamo as the source of electric current for the ignition.

In 1895 Benz & Cie were producing both the full-size vehicles such as the Viktoria and the Vis-à-vis, which cost upwards of 4,000 marks; and the small, lightweight Velo, which cost 2,000 marks. The Velo represented a reversion to Benz's original concept of a motorised velocipede. Its prototype had had three wheels and bore a striking resemblance to the rebuilt vehicle.

What was produced appears to have been based on the final form of Nr. 1, probably from early 1886. But it was not an exact copy: the technology of carburettors had advanced enormously over ten years and going back would have made it as hard to use as the original. The height of the platform above ground – 60 cm – may also have been lowered from an original 80 cm.

Date of technology in the 1895 rebuild

There are several features of the 1895 rebuild which are either manifestly from the mid-1890s or which do not conform to Benz's observed practice in the mid-1880s:

• the carburettor is an up-to-date one from the Benz Velo;
• the fuel tank is not where it was on patent DRP37435 or where it needed to be for Benz's carburettors of 1886 – 1890;
• the sight gauge is off the fuel line rather than on it and has been placed so that it cannot be read;
• the belt is crossed.

The carburettor of the 1895 rebuild matches that in Fig.164 of Baudry de Saunier's L'Automobile: Théorique et Pratique (1899). This is the carburettor from the mid-1890s which was being used in 1899 on the Benz Velo. It has a ballcock-type float valve, which Benz only introduced c.1893. How it worked is explained on pp.321-324 of Baudry de Saunier's book. The carburettor on patent DRP37435 was much more primitive; see the section Carburettor and Exhaust System for an explanation of this and the carburettor used on Nr. 2.

On patent DRP37435 fuel flowed by gravity from the fuel tank to the carburettor once the cock on the fuel tank had been opened. How much fuel flowed depended on how far the cock was opened. It then continued to flow, regardless of whether the engine was turning, until the cock was closed. There may have been an overflow pipe through which the carburettor could shed excess fuel (which would at least stop the carburettor filling completely). With such technology, it is understandable that those producing the rebuild should not seek faithfully to reproduce the original.

Sitting on the carburettor in patent DRP37435 was the fuel tank, which took the form of a squat vertical cylinder. In Nr. 2 the carburettor was a vertical cylinder next to the left rear wheel; the fuel tank cannot be seen. The 1887 photograph of the rear of Nr. 3 shows that by then Benz had implemented a device described in patents DRP43638 and CH970A by which fuel was metered out from the fuel tank for each revolution of the engine. This meant that if the engine stopped, so did the fuel flow.

It seems likely that this device was introduced during 1886, but exactly when is not known. It required the fuel tank to be close to the valve gear so that a rod from the valve gear could operate the rotating valve which controlled the fuel flow. That is why Benz placed the fuel tank under the seat and why the fuel tank on the 1895 rebuild is not consistent with the mid-1880s. Of course, once the fuel level in the carburettor was controlled by a float valve, the fuel tank could be placed anywhere.

Until Benz incorporated a float valve in his carburettors, they had a sight gauge on the fuel line. This was needed to be able to monitor the level of fuel. Once the fuel level was controlled by a float, a sight gauge was no longer needed. In his implementation of the ballcock float valve, Benz fixed a vertical rod to the top of the float which projects through the top of the carburettor. This rod goes up and down with the float and provides a direct read-out of the level of fuel in the carburettor. It can just be made out on the top of the carburettor of the 1895 vehicle on this photograph of it from the late 1890s

A sight gauge was included in the 1895 vehicle, but it lies off the fuel line (it must do so as the fuel enters from below, and the fuel line must be full of liquid for it to work as a siphon). As the carburettor has the float rod, which shows the fuel level, the sight gauge is redundant.

On the 1895 rebuild the sight gauge has been placed between the carburettor and the centre-line, as on Nr. 2. The image of Nr. 2 shows that on that vehicle the sight gauge could readily be seen from the left side. It cannot be seen from a comparable position on the rebuild (hence the view from below from the 3D model). This is because the carburettor lies further forward on the rebuild than on Nr. 2 and the wheel rim / tyre and the frame tubes get in the way. Benz needed to be able to read his sight gauge and arranged his parts so that he could. Those responsible for the rebuild copied the position of the carburettor on the side view of patent DRP37435 (which was before the engine was moved forwards) rather than that which Benz showed on patent CH960A and used in Nr. 2.

On all the images of the single-belt vehicles, including patent drawings DRP37435 and CH960A, and on the surviving Model 2, the drive belt is straight. Crossed belts appeared from 1890 with the two-belt Model 3 and continued with the Viktoria and the Velo. Crossing the belt makes the countershaft rotate in the opposite direction to the driveshaft, so if no other change is made, either the vehicle runs backwards or the engine has to turn the other way.

Final form of the motorised velocipede

Benz was developing his Motorwagen continuously over the period 1884 – 87. Twice within that period he gave it a new body. Patent DRP37435 shows the motorised velocipede as it was in late 1885. Its final form lies somewhere between those drawings and Nr. 2.

There is a further drawing from this period: Fig I of patent CH960A. Although the patent drawings were prepared for printing in November 1888, the original drawings are much earlier. Fig I is a side view of a calèche (i.e. Nr.3 and Model 2) with wheels larger than Benz used until 1892 on the Viktoria. While the vehicle in Fig I is not a motorised velocipede, the cushion, arms and back of the main seat match those of the 1895 rebuild. No other image shows that seat: after the uncushioned seat of patent DRP37435, the next seat is that within a wooden box on Nr. 2. Fig I corroborates the form of the seat in the 1895 rebuild as having been part of the Patent-Motorwagen between the vehicle in patent DRP37435 and Nr. 2. That gives a date to Fig I: between late 1885 and June 1886.

Fig I of patent CH960A shows a vehicle with:

• the engine moved forwards so that the flywheel hardly projects behind the rear wheels;
• supports for the seat in the shape used in Nr. 2 and the 1895 rebuild but made of metal bar rather than tube and (as in Nr. 2) without helical springs immediately beneath the seat;
• the steering stalk as in the 1895 rebuild;
• direct access from the side to the floor in front of the seat. On the patent drawings DRP37435 this was blocked by the front scroll support for the seat and by the drive/brake lever. By implication, the drive/brake lever has been moved back to beside the seat
• the carburettor just in front of the rear axle (i.e. where it was on Nr. 2).

Fig. I may represent what Benz wanted to build next after Nr. 1, but could not afford. Instead he built the less-ambitious motorised Stanhope gig. This incorporated the old engine from Nr. 1, probably with an increased stroke and new cylinder extension.

All but the final bullet point above are present in the 1895 rebuild; the carburettor remains where it appears in the side view in patent DRP37435 (but just inside the left drive chain rather than on the centre-line). The pastiche of patent drawings shows what the final form of Nr. 1 might have looked like. No drive/brake lever or coolant water reservoir is shown because these took a new form not in either patent drawing. Two carburettors are shown, one from each patent drawing.

If the changes listed above were made in Nr. 1, the main ones which remained to be made before June 1886 were:

• a new frame, tapered and rising towards the front;
• wooden wheels with iron tyres;
• reworked transmission using heavier-duty components for the greater weight of the new body;
• a reduction gearbox to provide a second, low gear, together with a stalk and hand lever to control its use;
• a new braking system with wooden block brakes on the tyres of the rear wheels.

These all involve the fabrication of new parts and their assembly as part of a new vehicle separate from Nr. 1. That would have taken a few months. Such fabrication could either have been done after Nr. 1 had been decommissioned or in parallel with continued test-running of Nr. 1. In either case, the engine from Nr. 1 would need to be transferred to the new vehicle and made more powerful with a longer stroke, new cranks and cylinder extension. Parallel activities seem probable, given that there is only half a year between the first public demonstration of Nr. 1 outside the plant and Spring 1886, when Benz "no longer shied away from people and their criticism", presumably because he now had a more presentable vehicle.

Height of the platform: one motorised velocipede or two?

The pastiche shows what Nr. 1 would have looked like with the cylinder and flywheel brought forward, a new seat, central steering stalk and (implied but not visible) the drive/brake lever moved next to the seat. The platform in front of the seat remains 80cm above the ground.

The 1895 rebuild has a lower platform, at 60cm. This was achieved by bending the frame tubes twice towards the front of the rear wheels and using a rising bent tube to the pivot of the front wheel. Such changes to the frame could not have been done in situ. The vehicle would have had to be disassembled so that the frame could be worked on. Alternatively, a new frame could have been made and the parts transferred. That is what some suggest:

Two motor cars were made in 1885 to this first design of Carl Benz; one of the vehicles is preserved in running order in the Deutsches Museum, Munich

If Nr. 2 was being fabricated in parallel with continued test-running and development of Nr. 1, there would seem little reason to stop the test-running of Nr. 1 to modify its frame. A second frame for Nr. 1 would be more likely if it preceded the start of building of Nr. 2. But that comes up against the short period between the first public demonstration of Nr. 1 outside the works (towards the end of 1885) and Benz's preparedness to be seen in Mannheim in his (presumably new) vehicle from Spring 1886.

When he produced the frame for Nr. 2, Benz tapered it between the seat and the front wheel. In front of the seat he bent the tube first downwards and then upwards on each side so that the frame lies above the front wheel and almost meets its pivot. At the back on each side the tube is horizontal above the elliptic spring and the rear axle. Benz thereby created a stronger and more resilient structure between the back of the vehicle and the pivot of the front wheel than in patent DRP37435.

Benz also bent the side tubes down in front of the seat and up above the front wheel in the drawings for patent CH960A. Fig I shows that he was contemplating a separate underframe, which was used to provide full suspension in Fig II and realised in Nr. 3. Fig II shows the frame tapering in front of the seat with the sides of the underframe meeting at the pivot of the front wheel.

Max Rose drew up the articles of Benz & Cie, Rheinische Gasmotorenfabrik in Mannheim for the company to do what the name said: make gas engines in Mannheim. He indulged Benz in his dream, but when he withdrew in 1890 made clear that he thought there was no future in horseless carriages. Benz knew where he stood and devoted his working day to gas engines. Benz didn't get a second cylinder cast during development, and when it was recovered from a stationary engine c.1895, the original cylinder had bore and stroke of 90 x 150. Later engines appear to have started "square" (i.e. bore = stroke) with the stroke being increased later.

All of this points to tight control of expenditure on Benz's personal project. It makes it unlikely that Benz would have created a second frame for the motorised velocipede which was so little changed from the first. Its effects could be predicted; the performance of the engine and transmission had to be established by testing.

By contrast, those responsible for the 1895 rebuild had to start from scratch. They did not have a vehicle. In building one, there was advantage in producing a motorised velocipede which was easier for its occupants to use. Lowering the platform to 60cm made it easier to get into and out of and less top-heavy, reducing the risk of its toppling over when cornering.

Occam's razor says that the simplest explanation is probably right. This is that in 1885 – 86 there was only one motorised velocipede and its platform was at 80cm.

Subsequent History

With the passage of time, the vehicle created in 1895 has come to be seen as a replica of Nr. 1. Its origins and purpose have been lost. Images of it outside the pharmacy in Wiesloch outnumber those of Bertha, Eugen and Richard in a Model 2.

At some time between 1900 and 1923, further changes were made. In the photos from 1900, it is completely open beneath the seat and the top of the cylinder head can be seen. By the 1920s, photos show slats being carried up beneath the seat, hiding the engine. Through them projects a knob to control the fuel/air mixture. These are included in modern replicas.

On 12 July 1925 the Allgemeine Schnauferl-Club organised a parade of historic vehicles in Munich which Benz headed, driving his Patent-Motorwagen for one final time.

Between 1925 and 1961 the bent tube to the pivot of the front fork was replaced. In 1925 it had a continuous curve but is now bent only in the middle. The geometry also changed: in 1925 the steering stalk leaned back and the front fork was vertical; today the steering is vertical and the front fork has a forward cant.

More recently, copper pipework, associated fittings and the base of the carburettor show signs that they have been replaced.

Most modern replicas (including those by Mercedes-Benz Group) duplicate the post-1925 bent tube and the canted front fork.

Mercedes-Benz Public Archive

At 18 May 2026 the Mercedes-Benz Public Archive's entries for "Model 3; 3 hp" included images of Nr. 2, Nr. 3 and Model 2 but not Model 3. The images may be identified as:

• 22389: Model 2 – this is a higher-resolution version of the out-of-copyright Fig. 27 of Benz's Lebensfahrt. Its caption there is Mein erster Serienwagen von 1888. 1,5 PS, 2 Geschwindigkeiten bis zirka 16 km/Std., damaliger Preis 3000 Mark (My first series-produced car of 1888. 1.5 h.p., 2 speeds to approx. 10 mph, original price 3000 Mark).
• 22390: Nr.3. – this is a higher-resolution version of the out-of-copyright image on Wikimedia Commons
• 22588: Nr. 2 – this was used as advertising in 1888; the report beneath from the Munich Neueste Nachrichten of 16 September 1888 references the exhibition in Munich and describes the vehicle as eine viersitzige Komfortable Kaleche mit umlegbarem Regenbach (a comfortable four-seat calèche with a fold-down rain-hood). The engraving of Nr. 2 was published on p. 80 of Worby Beaumont (1900): Motor Vehicles and Motors. A high-resolution version of it cropped to show only the vehicle is on Wikimedia Commons and is used in this article.
• 31809: Model 2 – Carl and Bertha Benz driving round Munich in their Model 2 in September 1888. This image (an engraving, not a photograph) was published in the Leipzig Neue Illustrirte Zeitung of 1 December 1888 and was subsequently reproduced in the Scientific American. It is out of copyright and on Wikimedia Commons.
• 82441: Nr. 2 – another copy of 22588
• B39394: Model 2 – this is a painting of the trip by Bertha, Eugen and Richard from Mannheim to Pforzheim in early August 1888.
• C42836: Model 2 – engraving from unidentified source of a Model 2 in a street around 1890 (as the parts of the engine which can be seen beneath the rear box appear more similar to those in the two-speed Model 3 than to Model 2, there must be doubts as to whether this image represents a real vehicle)

The entries for "Model 3; 2.5 hp" included some of those listed above together with images of the Science Museum's Model 2 when it was on loan to Automuseum Dr Carl Benz in Ladenburg. Among them is:

• 2008DIG1669: photograph of the Science Museum's Model 2 to the left of a modern replica of the 1895 rebuild of the original vehicle.

The entries for "Model 3; 1.5 hp" include some of those listed for the Model 3; 3 h.p and in addition:

• 22584: Nr. 2 – this is similar to 22588 and is an advertisement from a catalogue; if the catalogue was published, the image would now be out of copyright. It is based on a photograph which appears as Plate 4B in Nixon's The Invention of the Automobile (1936); this identifies the passenger as Max Rose, director of Benz & Cie. It offers the most detailed view of the engine of Nr. 2 and complements the photograph of the rear of Nr. 3.
• A33374: Model 3 – this shows Carl Benz driving a Model 3 with Josef Brecht beside him outside the Benz factory on Waldhofstrasse. It is evidently the basis of the engraving of Model 3 with the same occupants but in a Rhineland landscape with vineyards;
• 1988M51: Model 3 – 1892 advertisement for Model 3 quoting the price as 3000 Marks. This contains an engraving based on A33374 which was published on p. 81 of Worby Beaumont (1900): Motor Vehicles and Motors. A high-resolution version of it cropped to show only the vehicle is on Wikimedia Commons and is used in this article.

The description correctly identified the following image as being of Model 3 but it is not tagged to be returned in a search for Model 3:

• 1989M8: Model 3 – Eugen Zardetti and his family in a two-speed Model 3 on 19 March 1893. This is a higher-resolution version of the out-of-copyright image on Wikimedia Commons

At 18 May 2026 there were no entries for Model 2, but in addition to the images listed above, there was:

• 2007DIG2638: advertisement from 1888 for Émile Roger which shows (leftmost image) a Model 2 with a straight panel at the front rather than the rear-facing front seat.

At 18 May 2026 the entries for Model 1 mostly related to replicas of the 1895 rebuild of the original vehicle. Those which related to the rebuilt original vehicle itself were:

• 7689: this is a higher-resolution version of the out-of-copyright Fig 31 of Benz's Lebensfahrt
• 22680: this appears to be a retouched version of the out-of-copyright Fig 17 of Benz's Lebensafhrt
• 00159359: the "loose engine" of the 1895 rebuild on the bench.
• H3365: photograph of the rebuilt original vehicle being driven at the Baden-Baden Automobile Tournament, 10–15 July 1923;
• U17000: higher-resolution version of the photograph used as Fig. 38 of Worby Beaumont's Motor Vehicles and Motors (1900).