J, R. Mayer on Celestial Dynamics. 191 
For this smallest value, the orbit of the asteroid is circular ; 
for a larger value it becomes elliptical, until finally, with increas- 
ing eccentricity, when the value of 2a approaches infinity, the 
orbit becomes a parabola. In this last case the velocity is 
ox, |F—toe, 
re) 
or 85 geographical miles in one second. : 
If the value of the major axis become nagative, or the orbit 
assume the form of a hyperbola, the velocity may increase with- 
out end. But this could only happen when cosmical masses 
expressed by the formula 
e——GX aay 
gteat as the solar radius, or 96,000 geographical miles. 
What thermal effect ‘obrebpstil “such velocities? Is the 
effect sufficiently great to play an important part in the immense 
development of heat on the sun bain of 
his crucial question may be easily answered by the help o 
the receding considerations. According to the formula given 
at the end of Chapter II, the degree of heat generated by per- 
Cussion is . 
=0°000139° Xc?, . i 
Where ¢ denotes the velocity of the striking body expressed in 
metres. The velocity of an asteroid when it strikes the ae 
Measures from 445,750 to 630,400 metres; the calorific effect o 
2 . ' 
The relati : +h which an asteroid reaches the solar surface 
in nici ee ee of the sun’s rotation, This, 2b i as 
hy as the rotary effect of the asteroid, is without moment and may be neglec' 
This distance is to be counted from the centre of the sun. 
