The supplies must be furnished in any event, in order that the various departments may perform their allotted duties--coal for the engines, stationery for the clerks, ties and rails for the tracks, oils for the lubrication of the thousands of axles daily turning, passage-tickets for the travellers, and a thousand and one things which are absolutely necessary for the safe and efficient conduct of every railroad in active operation. Each item serves its purpose, and, properly assimilated, keeps alive all the functions of one vast and complicated system. It is easy to see, then, the importance, first, of proper economy in buying, and then a correct and systematic distribution of all supplies. On the Philadelphia & Reading Railroad, for instance, the annual supply bills aggregate more than $3,000,000, covering such supplies as those just mentioned, and, in fact, everything which is purchased and used in the operation of the road; so that on a large system like that, the commissary department requires no end of detail, both in the purchase and the distribution of all material. The expenditure for lubricating oils, waste, and greases alone amounts to more than $150,000 per annum, while the outlay for fuel represents about $1,200,000, and this is comparatively a small sum, since that road is a coal road, so called, and the cost for fuel, as a matter of course, is reduced to a minimum. There the store-room system, which has now been pretty generally adopted by many of the larger roads, is fully exemplified. With a General Store-keeper in charge, all supplies purchased are accounted for through him, and distributions are made daily among the sub-store rooms, which are located at convenient points; and they in turn distribute among the various departments, for consumption, all accounting daily to the General Store-keeper at Reading. To give an idea as to the quantity of material required in the service on such a road, it may be stated that from twelve to fifteen car-loads of supplies per day are shipped to various points. When we consider that an ordinary car will carry from fifteen to twenty tons of freight, we find that the annual requirements will average about four thousand car-loads, or, say, about fifty thousand tons, and if all the cars were made up into one solid train they would occupy fully twenty-five miles of track, and consume an hour and a half passing a given point running at the ordinary speed of freight-trains.