By way of conclusion of the foregoing chapters on curves, momentum, and springs, permit me to again call attention to the remarkable fact that a rear-driving Safety of absolutely rigid construction, striking an obstacle four inches high, loses one-half of its entire momentum and that of the rider. Think of it! Not that we often strike a four-inch obstruction, but that it does not take very many smaller to make one. Thus we are continually wasting strength when there is really no substantial necessity or occasion for it, and the writer, for one, feels ready to maintain that even double the weight (harmful as extra weight always is) in a machine is justifiable if in so increasing the weight we can do away with this most potent source of loss of energy. The bicycle, or single-track machine, too, affords an unusual chance for proper manipulation of momentum, and the rear-driver a special opportunity for the attachment of proper springs. In a two-track machine, on the other hand, we are compelled to supply springs with lateral motion as a necessary appliance for the comfort of the rider, which lateral motion results in loss of momentum and kinetic energy, whereas in the bicycle our comfort and energy are all confined to one plane; so that all we want now is to have our springs adroitly and amply applied to operate in this plane and no other, and we shall then find that we invariably save our momentum, preserve our comfort, and retain our strength. It will be a long time before we can expect to realize our dream of perfection in easy riding, or to find cyclers hunting for the rough roads; nor do we expect to see them peering eagerly forward through the misty morning, greeting the dawning obstacle as glad tidings of “Land ho!” but we do expect very soon to see the discomfort and loss of power now encountered in a great measure overcome. If some one will only get us over the sandy places as nicely as we can reasonably expect, in the future, to glide over the rough places, then we will all be happy. CHAPTER XI. SADDLES AND SPRINGS IN RELATION TO ANATOMY AND HEALTH. The problem of saddles in cycles is really one of the greatest moment, and will continue to be, so long as any pain or discomfort is felt upon the bicycle sufficient to discriminate against it in contradistinction to that of sitting on a buggy-seat and being carried over a comparable distance. Too little attention has been paid to this subject in the past, especially during the “Ordinary” _régime_. The general build of the Ordinary is such as to make it quite difficult to attach comfortable springs and saddles: many and various have been the attempts at improvement, but all have been marked by only a comparative degree of success. Were it not, however, for this success, small as it may be, in making saddles comfortable, the cycling fraternity would have had the entire medical profession down upon them, as some of them are anyhow.