Great as the room assigned to locomotives, greater must be yard-room for car-storage, in rough proportions, as the length of the locomotive to the average train length. It takes something approaching a genius to lay out the car-yards, particularly in the case of passenger terminals, which are almost invariably in the heart of great cities where land values are fabulously high. These yards, in order to earn the appreciation of the men who must operate them, must be easy of access and be of sufficient size to meet the heavy demands that are to be put upon them. To appreciate them, let us consider them in daily use. The heavy express which has discharged its baggage and passengers in the train-shed is hauled out to the yards by one of the sturdy little switch-engines that are eternally poking their way about the yards. The engine that has pulled it in from the road backs itself down to the roundhouse, without another thought of the train. Its responsibility ended as soon as the run ended in the train-shed. The engineer simply has to see that his locomotive is carefully put away in the roundhouse; and, on some roads, that his fireman cleans its upper parts before the next run out upon the line. The roundhouse crew is then supposed to take care of the rest of the engine. In the meantime, the stout little switching-engine has hauled the cars out to the yards, separating the Pullman equipment and placing day-coaches, baggage cars, and the like in a position by themselves. An effort is made to keep the equipment for the heavy through trains reserved, allowance being made for occasional changes for repair and maintenance. In the case of the local and suburban trains, their varying traffic requires varying lengths; and it is possible that two or three of the train-shed tracks contain a supply of extra coaches in order that emergencies of sudden and unexpected traffic may be met. The yards must afford full facilities for storing and cleaning cars. This last is a thorough operation, compressed air being used in many cases and to great advantage. Within, seats are thoroughly dusted, floors swept, woodwork wiped, while the railroad's pride in the outer appearance of its equipment is shown by the scrupulous care with which a small army of cleaners, ladders in hand, wash down the varnished sides of the coaches. In addition, both coaches and Pullmans must be stocked with linen and ice-water, lighting tanks filled and trucks inspected while in storage yards. Most elaborate provisions are made for the stocking of dining and buffet cars.