0. B. WARRING. 99 



As to college text books, with few exceptions they ig- 

 nore the subject. Those that do speak of it devote 

 a limited space to the gyroscope, and, so far as I have 

 found, none to the other gyroscopic bodies. 



In these papers I shall present the various phenomena 

 exhibited by these bodies, and offer what seems to me 

 their true explanation, fortifying each step by an ex- 

 perimental demonstration. How successful I shall be 

 is for others to decide. But, should my explanations 

 prove worthless, there will remain a somewhat large 

 residuum, independent of all theorizing, of what may, 

 in that case, be styled empirical laAvs and principles, 

 for each is the formulization of what these instruments 

 have actually done in my laboratory, and what they will 

 repeat before the Section. 



Some of these phenomena are not only new, but are 

 fairly startling in their apparent contradiction of familiar 

 laws. 



THE GYROSCOPE. 



Although it is not the oldest of these machines, I shall 

 take up the gyroscope first, for a complete discussion 

 of this instrument will render the solution of the prob- 

 lems involved in the others a matter of comparatively 

 little difficulty. 



The gyroscope, as usually made, consists of a heavily- 

 rimmed metal wheel, or disk, revolving freely in a ring, 

 as in fig. 1. In line with the axle is a projection, or lug, 

 having in its under side a conical indention to receive 

 the point of a standard on which it rests with perfect 

 freedom to move in any direction. On the other end is 

 an inverted hook with its point in the vertical plane of 

 the axis, but a little above it. 



The theoretical gyroscope of Gen. Barnard and others 

 is a solid of revolution with no supporting ring, and 

 moving around a fixed point situated in its axis of figure 

 at some distance from its centre of gravity. Such an 



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