It is claimed that the range of sound lies between 16 vibrations and 30,000 (about); in such extreme cases the molecules would require 1/16 and 1/30000 of a second to perform the same journey. It must not be forgotten that a mass moving through a given distance has the power of doing work, and the amount of energy it will exercise will depend on _its_ velocity. Now, a molecule of oxygen or nitrogen, according to modern science, is a _mass_ 1/250000000 of an inch in diameter, and an oxygen molecule has been calculated to weigh 0.0000000054044 ounce. Taking this weight traveling with a velocity of 1,512 feet a second through an average distance of 8/100000 of an inch, the battering power or momentum it would have can be shown to be in round numbers capable of moving 1/200000 of an ounce. Now, when the C^{3} tuning fork has been vibrating for some time, but still sounding audibly, Prof. Carter determined that its amplitude of stroke was only the 1/17000 of an inch, or its velocity of motion was at the rate of 1/33 of an inch in one second, or one inch in 33 seconds (over half a minute), or less than one foot in one hour. Assuming one prong to weigh two ounces, we have a two-ounce mass moving 1/17000 of an inch with a velocity of 1/33 of an inch in one second. The prong, then, has a momentum or can exercise an amount of energy equivalent to 1/200 of an ounce, or can overcome the momentum of 1,000 molecules. It would be difficult to discover not only how a locust can expend sufficient energy to impart to molecules of the air, so as to set them in a _forced_ vibration, and thus enable a pulse of the energy imparted to control the motion of the supposed molecules of the air for a mile in all directions, but also to estimate the amount of energy the locust must expend.