NATUEAL PHILOSOPHY. 195 



the tendency of the two rotations when combined with a foreign disturbance 

 being to produce equal and opposite conical motions, the result is the same 

 want of stability as if there was no conical motion in either direction." 



Proceedings of the American Academy. In a paper read before the American 

 Association Meeting, at Albanj^, by Prof. W. B. Rogers, on the above subject, 

 the following passage occurs : 



" It always affords a sort of intellectual surprise to perceive for the first time 

 the application of some simple and familiar mechanical principle to the grand 

 phenomena of astronomy ; to see that it is but one and the same set of laws 

 which govern the motions of matter on earth and in the most distant regions 

 of the heavens ; to perceive a celestial phenomenon, vast in its relations both 

 to time and space, and complex in its conditions, identified as to its mechani- 

 cal cause, with the rotary movement of a little apparatus on the table before 



us." 



A writer hi the New York Tribune also discusses the principles involved 

 hi the Gyroscope as follows : 



" There seems to be an inverse relation between the two motions. As the 

 spinning motion (corresponding to the diurnal motion of a planet around its 

 own axis) gradually dies away, the travelling motion (corresponding to the 

 annual revolution around the sun) increases in velocity ; but at first, when 

 whirling at a very rapid rate, the mass travels around the support only about 

 once in ten or fifteen seconds too slowly for the ' centrifugal force' due to 

 that (the annual) motion to be of any practical weight. The centrifugal force 

 of the particles, due to their very rapid motion around the axis or shaft of the 

 wheel, is of course immensely great, but as it acts equally in all directions, up, 

 down, and laterally, it is difficult to see by what authority the weight is 

 diminished in the least thereby ; and the evident absence of any very deep- 

 laid humbug in a toy which any one may purchase for a dollar or two and 

 operate for himself, has seriously excited the curiosity of thousands of earnest 

 practical men, and some space has been devoted to it in scientific and tech- 

 nical journals, without seeming to touch the root of the phenomenon. It has 

 been suggested by some that the intense rapid revolution might act on the 

 ah- in some way to resist the attraction of the earth ; or again, that sufficient 

 electricity might be evolved to aid in this effect ; while some have such weak 

 and confused ideas on ah 1 subjects that the simple words ' central forces' or 

 ' planetary motion' are considered very satisfactory and full explanations. 



"It will be found on trial that the experiment will succeed equally well in a 

 vacuum, and what is still more interesting, if possible, the absolute weight of 

 the whole is not affected in the least by the anomalous condition described. 

 "Whatever the position of the axis, as it hums gaily around with one end rest- 

 ing on nothing, the other extremity will be found always to pull on the string 

 or to press on the stand with precisely the weight due to the whole. This, 

 removes all apprehensions that nature's laws are about to collapse or decay, 

 and serves to take us a step nearer to an explanation of the secret, 



" Every particle in a whirling mass tends to pull from the centre with con- 

 siderable force. This, which is termed the centrifugal force of the particles, 

 although it does not contribute one iota to diminish its weight, tends very 



