ANCIENT LINEAGE OF THE AUTOMOBILE When it was first proposed to substitute steam propulsion for the horse it was not realized that a rail would furnish enough traction to permit of hauling heavy loads, and some of the early locomotives that ran on rails were provided with toothed wheels that engaged in racks alongside the rails. In fact, the earliest locomotives were not built to run on rails but on ordinary roads; in other words, they were automobiles. The motor car can therefore boast of a more ancient lineage than the railroad engine. Joseph Cugnot of France is said to have built a three-wheeled steam carriage in 1769 which was so top-heavy that it upset when making a sharp turn at three miles per hour. Several steam carriages were built in England in the eighteenth century, but they were not successful. The real father of steam traction was Richard Trevithic, of Camborne, Cornwall, whose first steam carriage, built in 1801, carried eight passengers. His third machine, built in 1804, was the first to run on rails. This was strictly a locomotive intended to haul cars. It ran with its load at the astonishing speed of five miles an hour. Trevithic was the first to exhaust the steam from the cylinders into the smoke-stack and thereby increase the draft through the furnace and generated steam at higher pressure. All the early locomotives used toothed gears to turn the driving wheels until George Stephenson introduced connecting rods to drive the driving wheels direct from the pistons. George Stephenson’s “Rocket,” built in 1829, won a prize of 500 pounds in a speed contest when it established a record of 24 1-6 miles per hour. It also established the doubtful honor of being the first mechanical speed monster to exact the toll of human life. On its prize run it ran over a man and killed him. STEPHENSON’S LINK MOTION [Illustration: FIG. 61.--STEPHENSON’S LINK MOTION]