106 AN EMPIRICAL STUDY OF GYRATING BODIES. 



hence, is for the most part outside of the limits of this 

 paper. 



I shall confine myself to two or three of his conclu- 

 sions, which can be experimentally tested. On page 

 530, vol. iv., we read : "If the rotary motion remained 

 constant, . . . the deflecting force 1 would be just 

 sufficient to lift the axis back to the original position.' 1 

 In another place 2 he says: "The descent of the gyro- 

 scope is due only to the loss of rotary velocity." And 

 in yet another 3 : " The axis (owing to the retarding in- 

 fluence of friction and the resistance of the air) slowly 

 falls." 



This is no slip of the pen, for he repeats it in many 

 places and forms, and evidently deems it an important 

 matter, as indeed it would be if true. As such, it enters 

 into his reasoning as to the path of the gyroscope in its 

 horizontal movement and elsewhere. 



Sir William Thomson, when describing his "gyro- 

 static balance " last summer, before the British Associa- 

 tion at Montreal, put forth substantially the same idea, 

 for he says: "A 'Motionless' gyroscope, to wit, his 

 'balance,' if frictionless, would continue its up and 

 down motion forever." 4 



On this supposed persistency depends the force of his 

 empirical illustration of the kinetic theory of matter, 

 derived from the assumed action of his " Gyrostatic 

 Balance." 



The writer of the article " Gyroscope "in the English 

 Cyclopedia, takes the same ground. Indeed, it seems 



1 This " deflecting force " he says on page 557, "is the sole agent in producing these para- 

 doxical effects." Yet he admitted that " the foregoing analysis " (all of his high mathematics), 

 "while it has determined its value, has thrown no light upon its origin !" He naively 

 adds : " It may be well to attempt to inquire how this force is created ! " One would think 

 so in a work expressly to explain the Gyroscope. This he then attempts to do, but without 

 the help of any of the higher mathematics. How successful he is the reader must decide 

 for himself. It seems to me that he sees the truth dimly, " as in a glass darkly." 



2 Amer. Jour. Ed., vol. v.. page 303. 



3 Amer. Jour. Ed., vol. iv., page 530. 



4 I shall discuss this " balance " hereafter. 



90 



