Page:Life in Motion.djvu/91

Rh receives a shock, and it again contracts. Then it again relaxes; but it does not relax so much as before, ere it receives the third shock, and successive steps become smaller and smaller as we ascend (see Figs. 34, 35, and 36).

By shortening the spring, we quicken the period of its vibration, and thus we increase the number of shocks per second. Now you observe the individual contractions are smaller and closer together; but if we look at the tracing carefully, we find the same stair-like character of the curve, only the steps are smaller (Fig. 35). Again, still further shorten