A soldier writing from one of the camps on the Potomac, thus alludes to the peculiar music made by ballets passing through the air:
It is a very good place to exercise the mind, with the enemy’s picket rattling close at hand. A musical ear can study the different tones of bullets as they skim through the air. I caught the pitch of a large sized Minie yesterday, it was a swell from E flat to F, and as it passed into the distance and lost its velocity, receded to D, a very pretty change. One of the most startling sounds is that produced by the Hotchkins’ shell. It comes like the shriek of a demon, and the bravest old soldiers feel like ducking when they hear it. It is no more destructive than some other bullets, but there is a great deal in mere sound to work on men’s fears. The tremendous scream is cause by a ragged edge of lead, which is left on the shell. In favorable positions of light the phenomena can sometimes be seen, as you stand directly behind a gun, of the clinging of the air to the ball. The ball seems to gather up the atmosphere and carry it along, as the earth carries its atmosphere through space. Men are frequently killed by the wind of a cannon shot. There is a law which causes the atmosphere to cling to the earth, or which presses upon it with a force at the surface, of 15 pounds to the square inch ; does the same law, or a modification, pertain to cannon balls in flight I do not remember of meeting with a discussion of the subject in any published work. It is certainly an interesting philosophic question.
The Weekly Pioneer and Democrat, Saint Paul, MN