If the same process were to be applied to the freight equipment, the paint-shop would be of almost unlimited size. But freight-cars are not varnished. They are merely painted with the best of time-resisting pigments, usually a dull and sombre red. The freight-cars literally go through a bath in the paint-shop. Expert painters stand, like fire-fighters, with a hose-nozzle in their hands. Through the hose the paint is forced, gallons upon gallons of it; and when it is all over the freight-car is a fine, even red, just like the painters themselves. The lettering is a quick matter, with the use of stencils. * * * * * There remain two other great divisions of a central plant of this sort--locomotive repair shops and car repair shops, for the needs of the immediate divisions with their heavy traffic. These shops, extensive in themselves, present no radical differences from the usual division shops which a great railroad maintains at every division operating point in order to keep its rolling stock in the best of order. They are used to make light repairs. The master mechanic is a discerning man. He must know and judge accurately when a disabled car or locomotive should go to the company's main shops, when the repairs can best be made at the local plant. It is one of the points upon which the economy of the shop system depends. On this matter of shop economy whole volumes might be written, and have been written. In the beginning of shop practices there was little system in these matters, just as the shop work was reckoned far below its real importance. One of the earliest of real railroads was the Columbia & Philadelphia--nowadays one of the main stems of the Pennsylvania's trunk line--and it was from the beginning a railroad of quite heavy traffic, double-tracked and reaching into a fat country. Yet a shop at Parkersburg, halfway up the line, employing forty men in all, was considered quite enough for the maintenance of equipment. If one of those early engines broke down at either terminal, the engineer, the fireman and perhaps the local blacksmith had to make their own repairs. Nothing was standard, not even the sizes of such simple affairs as nuts and bolts. Years of railroading have changed all this. The master-mechanics and the master car-builders meet in annual sessions; and by means of reports from their expert committees have been evolved standards in every detail of rolling stock--standard materials, standard compositions, standard sizes, even standards in nomenclature of railroad apparatus down to the smallest parts.