engines have many of their parts exactly alike, and any of these could be taken from one engine and fitted to another without difficulty, the result being to secure the greatest economy in effecting repairs. To such an extent is this principle carried, that when, as is sometimes the case, one of a pair of cylinders in an engine is damaged, a new cylinder can be straightway procured from the fitting shop and bolted to the remaining one, without any further fitting being required.
The nuts, bolts, pins, and a good many of the small parts are prepared, in an upper room over the fitting shop, by boys, who enter the works as apprentices, and remain at this work for some time before being drafted out as journeymen in the various branches.
The wheel shop, where the wheels and axles of the engines are constructed, is fitted with large and powerful machinery, suitable for the work which has to be carried on, some of the lathes being capable of turning a pair of wheels as much as 8 feet 9 inches in diameter. Interesting features in this shop are the "roughing lathe," in which seven cutting tools are employed at one time in "roughing out" the crank axles, and the "nibbling machine," designed for cutting out the "throws" in the cranks, and which has no less than 160 cutting tools arranged round the circumference of a large disc. An ingenious mechanical contrivance exists in this shop for lifting the wheels and axles into the lathes and other machines. It consists of a series of light jib cranes travelling on a single rail laid on the floor of the shop, parallel with the lathes, and worked by a cotton cord ⅜ of an inch in diameter, running at the rate of a mile a minute, by which motion is transmitted to the various parts of the cranes. These
