Ample precedent for the Granite Railway existed in England, where, since the reign of Charles II, wooden tracks, sometimes armored with iron plates, had been used as runways for coal cars from the pits to the nearest waterway. Within five years of the start of the Granite Railway, similar systems are recorded in the states of Pennsylvania, South Carolina, New York, and Maryland. At first, the motive power for these lines was supplied by gravity, stationary engines, or horses, but soon tiny steam locomotives were tried. Thus, in the year 1829, Peter Cooper built the famous _Tom Thumb_, a successful locomotive which used rifle barrels for flues. In the same year the _Stourbridge Lion_, “the first locomotive that ever turned a driving wheel on a railroad on the Western Continent,”[7] was brought by sailing vessel from England and started operation in Pennsylvania. The American steam railroad system was thus well under way by the time the lower courses of the monument were being raised. [7] _Annual Report of the Smithsonian Institution_, 1889. Bryant later described his railroad as having stone sleepers laid across the track, 8 feet apart. Upon these, were placed wooden rails, 6 inches thick and 12 inches high (replaced by stone within a few years). Spiked on top of these were iron plates, 3 inches wide by ¼ inch thick. However, at road crossings, stone rails were used, with 4-inch by ½-inch iron plates bolted on top. This “permanent” construction was also used on the double-track, inclined plane at the quarry. (Well-preserved vestiges of this “permanent” construction are visible today at the rise to the Bunker Hill Quarry.) Here, an endless chain allowed the loaded, descending cars to pull up the empty ascending ones. The standard gauge of American railroads is now 4 feet, 8½ inches, measured between railheads, a standard adopted after many years of confusion before the present gauge dimension was adopted. Although Bryant described his track gauge as 5 feet, this dimension was measured between the “bearing points” of the wheels on the tracks. If the bearing points are assumed to be the center of the treads of the wheels, his gauge is found to match closely the present standard gauge. This track gauge agrees with that adopted by the famous English railroad engineer, George Stephenson, at about the same time, after he had measured scores of carts used by his farmer neighbors. Possibly, both Stephenson and Bryant knew that their selected gauge had a very early beginning; for some historians suggest that the English carts were originally made to fit the ruts cut in the roads of Britain by the Roman chariots, many centuries earlier, during the Roman occupation of Britain.