C. B. WARRING. 163 



THE GYEOCYCLE. 



Tf a broad band (or hoop) be put snugly around the 

 gyroscope, an instrument (fig. 38) will be formed, differ- 

 ing from either thus far described in the fact that the 

 centre of form, of gravity, and of motion, coincide. 



A tinsmith will make such a band (about two inches 

 is a good width) for a trifle. The most remarkable thing 

 about this is its repugnance to rolling down hill, 1 and its 

 fondness for turning a rectilinear movement into a 

 spiral one. 



If the reader understands the previous instrument he 

 will find no difficulty with this. 



bohnenbergher's machine. 



This instrument, as usually constructed, consists of a 

 sphere concentric with three rings, so arranged as to 

 give freedom of movement in all directions, while the 

 centre of gravity and form is a fixed point. 



In my experiments I have used a form of my own 

 devising, which affords greater facilities for the study of 

 the horizontal and vertical movements than do any of 

 the instruments which I have seen figured in encyclope- 

 dias, or elsewhere. It is represented in fig. 39, and con- 

 sists of a common gyroscope suitably mounted. In the 

 plane of the wheel are two pins, y y, screwed into the 

 ring, as nearly as possible in a horizontal line, passing- 

 through the centre of gravity. 



They rest in slots in the semi-circular brass piece, 

 y A y, and permit the ring to revolve on them with very 

 little friction. The ring in the diagram is represented 

 as horizontal, so that only its side is seen. Attached to 

 this, and in line with the axis, is a pin, B, to which a 

 weight can be attached. 



I used the wheel instead of a sphere, simply because I 



lThe only limit to the steepness of the inclined plane is lack of friction. If smooth and 

 too high, the gyrocycle will slide down it— not roll. 



147 



