_Answer._ As the breaking of a spring or spring-hanger may cause a more serious accident, the engine and train should be stopped as soon as possible after it occurs. If the hanger is broken and there is a duplicate on hand, it should be substituted in place of the broken one. If there is no duplicate, then the spring should be taken down, and a wooden block be placed between the top of the driving-box and the frame to support the weight which before rested on the spring. In order to insert this block, if it is a front spring which is broken, it is usually best to raise the engine with jack-screws or run the back wheels on inclined blocks of wood placed under each of the back wheels. This raises the weight off from the front-wheels, and the block can then be inserted between the box and frame. If it is one of the springs over the back wheels which is broken, the front wheels should be run on the wooden wedges. Such wedges can soon be cut out of a cross-tie with an axe, or by sawing a square stick of wood diagonally it will make two such wedges. The end of the equalizing lever next to the broken spring must be supported by inserting a piece of wood under it. This will usually be held securely by the weight which is suspended from the opposite end, bearing the blocked end down on the block. QUESTION 527. _What should be done if an engine-truck or tender spring breaks?_ _Answer._ Very much the same course must be pursued that is employed when a driving-spring breaks, excepting that usually the weight can be lifted off from a truck-box easier by placing a jack under the end of the truck-frame than by the method described. Usually, too, each of the truck-springs supports the weight on two of the wheels, so that the two boxes must be blocked up. QUESTION 528. _What must be done in case the engine-frame is broken?_ _Answer._ Usually very little need be done excepting to exercise more than usual caution in running, and to reduce the speed. Of course the breakage of a frame may disable the engine, but ordinarily in such accidents that is not the case. QUESTION 529. _How can it be known if an eccentric has slipped on the axle?_ _Answer._ It is indicated at once by the irregular sound of the exhaust, or, as locomotive runners say, the engine will be “_lame_.” QUESTION 530. _When it is known that an eccentric has slipped, how can it be learned which is the one that is misplaced?_