At this time the English locomotives were built to carry 60 pounds of steam. The American builders adopted pressures of 120 to 130 pounds per square inch, the now generally standard pressures throughout the world. In the years 1836 and 1837, Baldwin built 80 engines. They were of three classes: 1st, with cylinders 12-1/2 inches in diameter and of 16 inches stroke, weighing 12 tons; 2d, with cylinders 12 by 16, and a weight of 10-1/2 tons; and 3d, engines weighing 9 tons, and having steam-cylinders of 10-1/2 inches diameter and of the same stroke. The driving-wheels were usually 4-1/2 feet in diameter, and the cylinder "inside-connected" to cranked axles. A few "outside-connected" engines were made, this plan becoming generally adopted at a later period. The railroads of the United States were very soon supplied with locomotive-engines built in America. In the year 1836, William Norris, who had two years before purchased the interest of Colonel Stephen H. Long, an army-officer who patented and built locomotives of his own design, built the "George Washington," and set it at work. This engine, weighing 14,400 pounds, drew 19,200 pounds up an incline 2,800 feet long, rising 369 feet to the mile, at the speed of 15-1/2 miles an hour. This showed an adhesion not far from one-third the weight on the driving-wheels. This was considered a very wonderful performance, and it produced such an impression at the time, that several copies of the "George Washington" were made, on orders from British railroads, and the result was the establishment of the reputation of the locomotive-engine builders of the United States upon a foundation which has never since failed them. The engine had Jervis's forward-truck, now always seen under standard engines, which had already been placed under railroad-cars by Ross Winans. In New England, the Locks & Canals Company, of Lowell, began building engines as early as 1834, copying the Stephenson engine. Hinckley & Drury, of Boston, commenced building an outside-connected engine in 1840, and their successors, the Boston Locomotive Works, became the largest manufacturing establishment of the kind in New England. Two years later, Ross Winans, the Baltimore builder, introduced some of his engines upon Eastern railroads, fitting them with upright boilers, and burning anthracite coal.