Philadelphia has recently produced a velocipede of an entirely new style. There are but two wheels, the seat sitting quite low between them. The novelty consists in a cog attached to the guiding-post, by means of which the rear wheel is made to follow directly in the track of the forward wheel. No matter how short the turn, both wheels make it at the same time, and the seat always remains parallel with the driving wheel. In other machines there is no guide to the rear wheel, and consequently the machine cannot be turned so readily when a collision is threatened. The new machine, which is called the “Keystone,” in honor of its native State, is substantially built, and so far as it has been tested in the riding school, is pronounced a success. There is an ingenious gentleman in Cincinnati, who is at work constructing a velocipede to be propelled by a spring, on the principle of a watch. After winding it up, he calculates that it will move two miles before it will require winding. A gentleman in Albany has arranged a velocipede to run on railroad tracks. The wheels have flanges to them, so that they cannot leave the rails. The flanges are so arranged as to be removed when occasion requires, so as to make the machine available on ordinary roads. The inventor claims fifty miles an hour. An expert velocipedestrian in the West, has had rubber tires put upon the wheels of his vehicle; and finds by their use, he can ride in winter over snow and ice without slipping, and that in summer he is much relieved of the jar from roughnesses of roads. The vast majority of the new velocipedes of which we hear daily, prove total failures on trial. Most of their inventors proceed upon abstract principles, and fall into absurdities, from which previous practical knowledge would have saved them. [Illustration] VELOCIPEDES FOR LADIES. We present a bicycle for ladies, lately invented and patented by Messrs. Pickering & Davis of New York City. It will be seen that the reach or frame, instead of forming a nearly straight line from the front swivel to the hind axle, follows the curve of the front wheel until it reaches a line nearly as low as the hind axle, when it runs horizontally to that point of the hind wheel. The two wheels being separated three or four inches, allow of an upright rod being secured to the reach; around this is a spiral spring, on which a comfortable, cane-seated, willow-backed chair is placed. This machine, with a moderate sized wheel (of thirty to thirty-three inches), will allow being driven with a great deal of comfort and all the advantages of the two-wheel _veloce_. In mounting, a lady has to step over the reach, at a point only twelve inches from the floor, the height of an ordinary step in a flight of stairs.