192 ' J. R. Mayer on Celestial Dynamics. 
the percussion is consequently equal to from 274 to 55 millions 
of degrees of heat.* 
An asteroid, therefore, by its fall into the sun developes from 
4600 to 9200 times as much heat as would be generated by the © 
combustion of an equal mass of coal. 
V. The Origin of the Sun’s Heat (continuation). 
The question why the planets move in curved orbits, one of 
the grandest of problems, was solved by Newton in consequence, 
it is believed, of his reflecting on the fall of an apple. 
story is not improbable, for we are on the right track for the 
discovery of truth when once we clearly recognize that between 
great and small no qualitative but only a quantitative difference 
exists-—when we resist the suggestions of an ever active Imagine 
tion, and look for the same laws in the greatest as well as in the 
smallest processes of nature. mm 
is universal range is the essence of a law of nature, andt 
touchstone of the correctness of human theories. We ia 
the fall of an apple and investigate the law which governs ‘a 
phenomenon; for the earth we substitute the sun, and for t 
apple a planet, and thus possess ourselves of the key to the me 
chanics of the heavens. i 
As the same laws prevail in the greater as well asim ¥ 
smaller processes of nature, Newton’s method may be used 2 
celestial distances, we obtain a generation of heat exceeding al 
terrestrial measures, And since we have sufficient reas?” 
The fact that the development of heat by mechanical — 
on the surface of our globe is, as a rule, not so great, ra cam : 
. is 
heat generated by a weight falling from a height of 367 mete of 
* Throughout this memoir the degrees of heat are expressed in the given 
‘Bea Unless stated to the contrary, the measures of length args metres, 
geographical miles, A, r phen wile <2, of degree of latitude = 
and an English mile =1609 metres. ] 
