the driving mechanisms, its center line being 61 inches (155 cm) above the floor. There were 200 tubes, 2 inches (5 cm) in diameter and 7 feet (2.1 metres) long; the firebox was 4.5 feet (1.4 metres) square. The crown sheet was arched, and inclined downward at the back end to allow of climbing and descending grades equal to 15% without exposing any uncovered part to the fire (and so causing an explosion). The cylinders were 12 by 22 inches (30 by 56 cm); their center lines were placed 18 inches (45 cm) above the floor, and 61 inches (155 cm) apart. The piston rods connected with independent crossheads gliding upon steel girders, supported at their ends by standards bolted to the floor beams. The driving wheel axles extended through a sliding box containing the journals. The boxes slid in cast iron runners placed at right angle to the line of the engine, and each axle had a crank keyed upon its upper end. The well known slotted yoke connection was used. The slide valves were of the usual locomotive form. The links were placed in a horizontal instead of a vertical position, and were operated by two bellcranks. The throttle valve, link rod, brake and coupling rods, also the connection between the driving boxes for producing pressure against the rails, were operated by hydraulic power, although hand levers were also provided. Adhesion of the driving wheels to the rails was obtained by means of a cylinder and piston secured to the sliding boxes. The engineer had before him five hydraulic cocks, which adjusted the throttle, links, sliding boxes of the driving wheels, brakes and the coupling rods of the entire train, while just above were steam and hydraulic pressure gauges and indicators, whistle and bell ropes. The fireman was stationed behind the boiler, at the rear of the locomotive and so well away from the engineer. The reference to a control for coupling rods was as regards a claimed safety feature: One turn of the cock controlling the couplings unlocked them and divided the train into its component cars, each of which had a brake which acted automatically upon detachment from the train. This partially destroyed the momentum of the whole, and a collision could only take place by a succession of comparatively light blows from the engine and slowing cars of the train, instead of by a single