A. Yes; sometimes mountains, trees, and steeples, will discharge a lightning cloud floating near; and sometimes electric fluid rushes out of the earth, into the clouds.
Q. What produces electricity in the clouds?
A. 1st—The evaporation from the earth’s surface.
2ndly—The chemical changes perpetually going on: and
3rdly—Currents of air of unequal temperature, excite electricity by friction, as they pass by each other.
Q. How high are the lightning-clouds from the earth?
A. Electrical clouds are the lowest of all clouds; they are rarely more than 700 yards above the ground; and sometimes, they actually touch the earth with one of their edges.
Q. How high are the clouds generally?
A. In a fine day, the clouds are often 4 or 5 miles above our head; but the average height of the clouds is from 1–½ to 2 miles.
Q. Why is lightning sometimes forked?
A. When the lightning-cloud is a long way off, the resistance of the air is so great, that the electrical current is diverted into a zig-zag course.
Q. Why does the resistance of the air make the lightning zig-zag?
A. As the lightning condenses the air, in the immediate advance of its path; it keeps flying from side to side, in order to pass where there is the least resistance.
Q. How does lightning condense the air in the immediate advance of its path?
A. The air is condensed by the rapidity of the lightning-flash.
Q. Why is forked lightning more dangerous than a straight flash?
A. Whatever resists the flash, diverts its course; and when terrestrial objects offer resistance to the current, they are in great danger of being destroyed.
Q. Why are there sometimes two flashes of forked lightning at the same moment?
A. Sometimes (in very severe storms) a flash of lightning will divide into two or more parts; and then each branch assumes the zig-zag form.
Q. Why is the flash sometimes quite straight?
A. When the lightning-cloud hovers near the earth, as the flash meets with very little resistance, it is not diverted; or (in other words) the flash is straight.
Q. What is the cause of sheet lightning?
A. It is only the reflection of distant flashes, not distinctly visible: and sometimes several flashes (from different clouds) intermingle, and form one vast blaze or sheet of lightning.
Q. Which form of lightning is the most dangerous?
A. The ball of fire is by far the most dangerous; and the zig-zag lightning is next in danger. Sheet lightning is not often attended with danger.
Q. Why are balls of fire so very dangerous?
A. Because (whenever they fall) much mischief is occasioned by their bursting, which they always do, with an explosion like that of a cannon.
Q. Do these balls of lightning ever run along the ground?
A. Yes; they often run a considerable way along the ground, then stop for a little time, and burst in numberless pieces: sometimes each of these pieces will explode; and at other times, the whole ball will burst at once, producing most mischievous consequences.
Q. What mischief will these balls of fire produce?
A. They will set houses and barns on fire; and kill all cattle and human beings, which happen to be in their course.
Q. Why does lightning sometimes kill men and beasts?
A. When the electric current passes through a man or beast, it produces so violent an action upon the nerves, that it destroys life.
Q. When is a person struck dead by lightning?
A. Only when his body forms a part of the lightning’s path: i.e. when the electric fluid (in its way to the earth) actually passes through his body.
Q. Why are men sometimes maimed by lightning?
A. Because lightning strikes with amazing force, whatever opposes it: and if a man stand in the way, it strikes him such a blow, as to maim him.
Q. What is thunder?
A. Lightning parts the air through which it passes; and when the parted air closes again, the noise made by the concussion, is called Thunder.
Q. Why does lightning part the air through which it passes? It does not part a rod of iron.
A. Iron is a conductor, and therefore allows the fluid to go freely through it: but air being a non-conductor, resists the lightning; which, therefore, rips it open, in order to pass through it.
Q. Why is thunder sometimes one vast crash?
A. When the lightning-cloud is near the earth, as the flash is straight—the whole volume of air (through which it passes) collapses at once; and produces one unbroken sudden crash.
Q. What is meant by the air collapsing?
A. When the rent air closes again, it is said to collapse.
Q. Why is the peal sometimes an irregular mangling broken roar?
A. When the lightning-cloud is a long way off, as the flash is zigzag, the air does not collapse all at once; and as we hear the concussion of one part after another, the peal is broken, protracted, and irregular.
Q. Which part of the collapsing air do we hear first?
A. That part nearest the earth; then the strata above; and last of all, that in the immediate vicinity of the cloud.
Q. What is meant by “strata of air?”
A. If a board were laid upon the earth, and several other boards were piled upon it, this pile would represent strata of wood.
Q. How does this illustration apply to the air?
A. A
