88 
The American Geologist. 
February, 1696 
9. “Would not the sudden arrest of a mass of matter like a 
meteorite produce a noise similar to that .heard by the sudden 
action of the force which starts a cannon ball? Would not 
the resistance of the air be such as to cause a comparatively 
sudden arrest of the motion of a meteorite?” 
The arrest of the motion of a meteorite by the atmosphere 
may be regarded as comparatively sudden, yet there is a slow¬ 
ing down of its velocity as the meteorite passes continually 
into a more dense atmosphere, so that it falls to the earth with 
a speed comparable to that of an ordinary falling body. In 
several ways, however, the agencies producing sound differ in 
this case from that of the force which starts a cannon ball. 
The latter is local in its effect and of but momentary duration. 
The passage of a meteorite, on the contrary, as previously 
noted, leaves behind it a long narrow column of expanded air 
whose subsequent contraction will bring to the ear a long con¬ 
tinued sound. The character of the sound will depend upon 
the hight of the meteor, its size, velocity and the configura¬ 
tion of the country over which it passes. 
Gould a cannon ball, which, moving at the velocity ordina¬ 
rily given to it, whistles, have imparted to it a velocity of 
100,000 meters per second, it would no longer whistle, it would 
thunder. Conversely, meteorite fragments which ordinarily 
fall at a velocity so great as to thunder, will, if their velocity 
is decreased, produce only whizzing, whistling sounds. The 
fact, therefore, that sounds like the “whistle of a rifle bullet,” 
“the hum of a locomotive,” “the tearing of linen” and the 
“flapping of wings” frequently accompany the fall of meteor¬ 
ites, proves the arrest of motion of some of the fragments at 
least to have been simply such as to slow down their velocity. 
Some meteorites, moreover, have fallen without any explo¬ 
sive sounds. That of Mazapil, for instance, gave only a loud 
hissing noise, “ exactly as if something red-hot had been sud¬ 
denly plunged into cold water.” At the falls of Segowlee, 
St. Denis-Westrem, Shalka, Gross Diwina, and others, only 
low rumblings were heard. 
If the arrest of the meteorite by the atmosphere were the 
only cause of explosive sounds, it would seem that these 
should be as constant an accompaniment of a fall as the 
report of a gun or cannon is of its discharge. 
