of attempts s were made in England to produce a steam locomotive, Richard Trevithick (q.v.), a Cornish mining engineer, built several steam carriages for common roads and one engine to run on rails, but they were all failures although they possessed the elements that would have produced a successful locomotive in the hands of a persistent inventor. The first man to build a locomotive to run on rails and haul cars regularly was William Hedley, chief engineer of Wylam colliery on the River Tyne, near Newcastle, England. His first engine was not a success but his experience with its shortcomings enabled Hedley to build a second locomotive which worked fairly well, and is now to be seen in the South Kensington Museum, London, bearing the name of "Puffing Billy."

This engine (figure 1), which was built in 1813, had a return flue boiler, had upright cylinders and was a sort of grasshopper type of locomotive, which under a variety of modifications

gine, the front pair being the drivers, to which power was transmitted from two outside cylinders placed diagonally across the boiler pointing backwards. The first improvement made was to drop the cylinders to nearly a horizontal position which was followed by the cylinders being placed in the smoke box transmitting the power through a cranked driving axle. Most of the locomotive builders in Great Britain readily recognized the merits of the simple form of engine introduced by the Stephensons and they proceeded to develop the motor on similar lines. Stephenson's Rocket.-There was no original feature about the Rocket, all the elements having been previously employed by other engineers, but the combination was the work of a master mind and gave to George Stephenson, (q.v) the reputation of being the inventor of the locomotive which is more than his due. When the locomotive is closely analyzed, we find that no proof exists of George Stephenson having

became the fashion and held the field up to 1829, when the directors of the Liverpool and Manchester Railway offered a prize for a locomotive that would fulfill certain practical requirements. A variety of locomotives were entered for competition and the prize was awarded to the " Rocket," made by George Stephenson & Son. This engine gave a new type of locomotive to the world which by mere increase of size is the locomotive of the 20th century.

Essential Elements of a Locomotive.-The elements combined to make a locomotive engine successful are a boiler that will generate steam rapidly and simple mechanism that will transmit the power directly to the driving wheels. The Rocket had a multitubular boiler, combustion being stimulated by exhaust steam passing through the smoke stack; and the cylinders transmitted the power to the driving wheels without the intervention of any useless beams or rods and the mechanism could be easily handled by one man.

The Rocket (figure 2) was a four wheel en

invented anything which became a permanent attachment. The tubular boiler had been applied to a boiler by Marc Seguin, a French railway master mechanic, several years before the Rocket was built, they were used in the United States in marine boilers before Stephenson's time, and the steam jet in the chimney had been used by Trevithick, Hedley, and others. But if Stephenson was deficient in inventive attributes he had the faculty of knowing a good thing when he saw it. He was one of the first men in Great Britain to realize that there was a great future for the steam engine as motive power for land transportation and he persisted in promoting the interests of the locomotive when it had few influential friends. Stephenson was a good representative of the best type of Englishmen. Opinionated and ever pushing his opinions with bull dog tenacity, he made weaker minds yield before his views on railways and locomotives. This was his hobby and he rode it so furiously that the British world was drawn along often against its will. By his dominant will, persist

ent determination and forcible arguments, he prevailed on British capitalists to construct an expensive railway for general transportation and induced them to try locomotives when all the scientific world insisted that locomotives were impracticable. He gave his country the glory of originating steam operated railways at the moment when America was almost ready to grasp the prize of honor.

Within a year after the Liverpool and Manchester Railway was opened, a host of other railway enterprises were in progress. The first locomotive almost universally used at that time was carried on four wheels, one pair of small carrying wheels close to the smoke box and one pair of driving wheels in front of the fire box. The boiler was about nine feet long and included an internal fire box about three feet long. The furnace in the Hedley and other early locomotives was located in the internal flue, which in some cases provided the whole of the heating surface; in other cases an addition of a return flue was made. When the Rocket was designed it was determined to employ small tubes to convey the heat of combustion to the water in

the boiler, a change which involved the use of a fire box as a furnace. That was made of rectangular section with flat walls which had to be strongly stayed to the outside shell, a water space being provided between the two surfaces. A smoke box with length about one quarter the diameter of the boiler was provided for the passage of the fire gases on their passage to the chimney. In the smoke box was located the opening of the steam exhaust pipe pointing straight through the center of the chimney and acting as a draft inducer. This combination of a multitubular boiler, a fire box surrounded by water and an exhaust steam jet located in the smoke box form the combined elements which make a high speed locomotive a possibility. They were first used together in the Rocket.

Development of the Locomotive in Europe. -The line of development exerted upon the locomotive was increasing the number of wheels and the proportions of boiler cylinders and running gear. In Europe the engine was at an early day provided with a pair of carrying wheels under the foot plate, The wheel arrangement then was one pair of small carrying

out any carrying wheels. That remained almost the universal practice until about 1900 when four pairs of driving wheels coupled began to find favor. On railways on the continent of Europe, British practice was closely imitated for years but in some cases very heavy multicoupled wheel locomotives were used for freight service. In the British Isles inside cylinders were preferred with a plain slide valve operated by a link motion; on the Continent outside cylinders found most favor and articulated valve motion is more in favor than the link motion.

Genesis of Railroads in America.-The movement in favor of building railroads began in the United States about the same time as it began to influence public opinion in Great Britain. The 19th century had not advanced many years when people in the United States commenced to realize the urgent necessity for good arteries of intercommunication as a means of developing the extensive unsettled territory of the country. Statesmen were aware that the immense regions comprising the Roman Empire had been tied to the central government by a system of magnificent roads. There are numerous long reach