16 SIR ROBERT §. BALL, LL.D. IRS, ON 
produced by the collision of those two bodies is equivalent to 
the amount of heat produced, which is sixteen hundred times 
as great as all the heat that could be produced by the 
burning of two masses of coal as big as those two bodies. 
Is it any wonder, then, that by nth a collision a flash can 
be produced that carried its message throughout the whole 
extent of millions and millions of miles between where we 
are situated and where that incident took place? Such we 
believe to be the origi of this star. We are not left 
altogether to speculation in regard to it. There are many 
other confirmatory circumstances. In fact, remembering 
the myriads of such bodies that are there it is exceedingly 
likely that such a collision should occur, and that it should 
produce such an effect as we have seen. If any one doubts 
that a collision can produce such a glorious radiance they 
have only to look at the shooting stars. A shooting star 1s 
a brilliant streak of light. In one brief fraction of a “second 
that little object is transformed by a temperature far greater 
than we could produce in our most powerful furnaces into 
heat. It can be shown that an object a child can carry 
would, if it were launched as a meteor dashing into our 
atmosphere, produce sufficient light to astonish a large part 
of the earth. It has been calculated that a meteor which 
appeared in America some months ago and was not heavier 
than a pound or so, produced so much light and heat by 
collision with the air, that the hight was as great as could be 
produced by an electric engine driven by a 40,000 horse- 
power engine, and the noise that it made was as great as if 
that light’ were accompanied by music from foe-horns, blown 
by another 40,000 horses. 
I must add a few words as to the process of evolution, so 
o speak, which we see going on around us in the heavens. 
This subject has come very much before the attention of 
astronomers lately in consequence of discoveries that have 
recently been made. One of the greatest of philosophers, 
Immanuel Kant, laid the foundation of that remarkable 
nebular theory which ordinar ily goes by the name of Laplace. 
Had Laplace and Sir William ‘Herschel lived to these days, 
they would have heard with unbounded interest of the 
development of our knowledge which has arisen from 
photography. Here* is another point in the heavens, and 
here is some trace of the nebulous material—this elowing 
* Pointing to the screen. 
