Philosophical Facts
The greatest height at which visible clouds ever exist does not exceed
ten miles.
Air is about eight hundred and fifteen times lighter than water.
The pressure of the atmosphere upon every square foot of the earth
amounts to two thousand one hundred and sixty pounds.
The violence of the expansion of water when freezing is sufficient to
cleave a globe of copper of such thickness
as to require a force of
27,000 pounds, to produce the same effect.
During the conversion of ice into water one hundred and forty degrees of
heat are absorbed.
Water, when converted into steam, increases in bulk eighteen hundred
times.
In one second of time--in one beat of the pendulum of a clock--light
travels two hundred thousand miles. Were a cannon ball shot toward the
sun, and were it to maintain full speed, it would be twenty years in
reaching it, and yet light travels through this space in seven or eight
minutes.
Strange as it may appear, a ball of a ton weight, and another of the
same material of an ounce weight, falling from any height will reach the
ground at the same time.
The heat does not increase as we rise above the earth nearer to the sun,
but decreases rapidly until, beyond the regions of the atmosphere, in
void, it is estimated that the cold is about seventy degrees below zero.
The line of perpetual frost at the equator is 15,000 feet altitude;
13,000 feet between the tropics; and 9,000 to 4,000 between the
latitudes of forty degrees and forty-nine degrees.
At a depth of forty-five feet under ground, the temperature of the earth
is uniform throughout the year.
The human ear is so extremely sensitive that it can hear a sound that
lasts only the twenty-four thousandth part of a second.
Sound travels at the rate of one thousand one hundred and forty-two feet
per second-about thirteen miles in a minute. So that if we hear a clap
of thunder half a minute after the flash, we may calculate that the
discharge of electricity is six and a half miles off.