War changes Weather

There have been questions about the claims and effectiveness of 'hail cannon' which use focused explosions to disrupt clouds before hail has formed. This is to protect crops from the damage done from hailstorms.

So, I happened across a review of an old book published in Silesia, with the name of 'Aphorisms, respecting the Influence of War on the Atmosphere, Weather and Fertility on the Earth' which records the authors' observations regarding said effects.

If a cubic foot of gunpowder, when it explodes, exercise a force equal to twenty-nine millions of pounds, it by these means produces a great change in the elasticity of the air; the whole mass of the atmosphere within a large circumference is violently torn, and billows of air are produced, which roll themselves upwards and agitate the vapours contained in them.

It cannot therefore be denied, that the discharging of firearms and cannon during battles and sieges, and even at great military troop reviews, must have an influence on the atmosphere and on the state of the clouds and weather. The author quotes instances, in the time of the Seven Years War, of clouds and vapours being dispersed by the explosions of the cannon, and asserts that during his travels through the Tyrol, he saw on several occasions, to use his own expression, the clouds 'shot dead.'

He observed in the neighborhood of Leignitz, while the regiment of Wartensleben were going through their exercise, that the clouds were broken by the explosions, and that the murmuring of the wind and the agitation of the leaves of the trees and small feathers suspended from any body, were sometimes stronger, sometimes weaker, according as the troops fired by battalions or companies.

The barometer rose and fell at each explosion, and water in a vessel at a distance of five hundred paces was violently agitated. There have been instances of the noise by heavy cannonades being heard at the distance of more than forty miles.

It is natural to suppose, too, that the thunder of cannon must penetrate even into the interior parts of the earth, and to the bottom of the sea; and Dutch fishermen have, accordingly, remarked that every great naval engagement had the effect of frightening the fish far away from the scene of action, near which none are to be met with for a long time after.

Additionally, the quantity of gunpowder fired in time of war may have a sensible effect on the fertility of gardens and fields.