QUESTION 299. _How are the spring-hangers attached to the ends of the springs?_ _Answer._ A great variety of methods have been used. The most common ones are those shown in fig. 169. There the hanger embraces the spring at the ends, _g_, _g_, (shown on an enlarged scale at _a_, in figs. 176 and 177.) The end of the spring has two projections forged on its end to receive the upper end of the hanger, which is made to fit the groove thus formed between the two projections. The other end, _b_, of the spring, figs. 176 and 177, has an eye cut in it which receives the hanger _b_. The latter is made of a single bar, and also has an eye, _c_, to receive a key which sustains the weight suspended on the hanger _b_. The back end of the front springs and the front end of the back springs are made in this way because they come on the side of the fire-box, and if their width was increased by the thickness of the hanger, as shown at _a_ in fig. 177, it would rub against and wear the outer shell of the fire-box. QUESTION 300. _How are the lower ends of the hangers attached?_ _Answer._ The front hanger, _g_, fig. 169, of the front spring, and the back hanger, _g_, of the back spring have eyes and pins in their lower ends, _k_, as shown in the engraving. The pins are supported by rubber springs, _l_, _l_, which are held between two concave castings, _n_, _k_, one of each of which rests against the frames. The object of the rubber springs is to relieve the spring-hangers from sudden shocks and strains. The benefit derived from their use is believed to be purely imaginary, as the spring itself, if sufficiently elastic, should absorb the sudden shocks which the wheels and axles will convey to the hangers. QUESTION 301. _Why are the ends g′, g′ of the springs attached to the lever_[75] _A A?_ [75] This lever is called an _equalizing lever_ or _beam_, or, more briefly, an _equalizer_. _Answer._ Because if there is a spring for every axle and the hangers are fastened to the frame, then evidently the locomotive has as many points of support as it has axle-boxes. Every shock from the rails is transferred through the wheel and the axle to the nearest axle-box and the spring belonging to it, and the latter must be made strong enough to receive and dispose of the whole of it. If the adjacent hangers, _g′_, _g′_, fig. 169, of the adjoining springs, _B_ and _B′_, are connected by an equalizing lever, _A A_, which turns on the fixed point _C_, then the shock which affects one wheel will be transferred first to the corresponding spring. From this spring a part of the shock will be transferred to the frame by the hanger _g_, and a part by the hanger _g′_ to the equalizer, which will transfer the pressure to the adjoining spring _B′_. If by some unevenness of the road or a powerful oscillation of the locomotive, a spring is momentarily burdened, the equalizer thus causes the next wheel to receive part of this load.