622 
Correspondence . 
[October, 
12. Conformation and Size of the Hailstones. 
13. General character of the weather before and after the 
storm. 
I should also be glad to receive references to previous memoirs 
on hail, or accounts of storms. 
You will much oblige by giving publicity to this. — I am, &c., 
F. A. B. Oliver. 
Athenaeum, Glasgow, July 26, 1881. 
AERIAL NAVIGATION. 
To the Editor of The Journal of Science. 
Sir, — I venture to trespass still further on your forbearance, in 
continuation of my letter on “Aerial Navigation,” in your issue 
for August. 
I cannot deny that I fear there may be such horrors as you 
hint at, as the concomitants of the immediate beneficial results 
of the practical solution of this problem. So long as men’s 
minds are blind to the full blessings of progress, the “ ape and 
tiger” lurking in most of us will come into view on suitable 
opportunities. Let us hope, however, that the development of 
communications will ever tend to exercise its educating and 
humanising power over “the ruder, less civilised portions of the 
globe though whether the more civilised and more enlightened 
nations will awake to the conviction of the worse than waste of 
war, without a rude shock, it is vain to foretell. 
But must the car of progress be stopped because some infatu- 
ated spectators may make it a car of Jaganat to their fellows and 
themselves, and because the world may abuse the mental, moral, 
and material gifts it brings ? Must ( e.g .) chemistry cease to add 
to the wealth and comfort of man, because desperate or dastardly 
individuals use some of its discoveries to further their own un- 
principled ends ? 
The war fiend appropriates to its own devilish ends the 
triumphs of Steam and Electricity. Must these be therefore 
discredited, and because their power for good may be largely 
discounted by their power for evil ? Must, then, progress be 
delayed until man is fit to receive its fruits ; or should we (like 
Victor Hugo) “ believe in all kinds of progress,” and endeavour 
to educate man to refrain from abusing his new wealth ? Should 
we not hope that thus, and that soon, “ the common sense of 
