Snap But In The Great Operations Of Nature The Light Is What We Call Lightning And The Sound Produced At The Same Time Though





generally arriving later at our ears than the light does in our eyes)

is, with its echoes, called thunder.



If the communication of this fluid be by a conductor, it may be

without either light or sound, the subtle fluid passing in the

substance of the conductor.



If the conductor be good, and of sufficient bigness, the fluid passes

through it without hurting it. If otherwise, it is damaged or

destroyed.



All metals, and water, are good conductors. Other bodies may become

conductors by having some quantity of water in them, as wood and other

materials used in building, but not having much water in them, are not

good conductors, and therefore are often damaged in the operation.



Glass, wax, silk, wool, hair, feathers, and even wood perfectly dry,

are non-conductors: that is, they resist instead of facilitating the

passage of this subtle fluid.



When this fluid has an opportunity of passing through two conductors,

one good and sufficient, as of metal, the other not so good, it passes

in the best, and will follow in any direction.



The distance at which a body charged with this fluid will discharge

itself suddenly, striking through the air into another body that is

not charged, or not so highly charged, is different according to the

quantity of the fluid, the dimensions and form of the bodies

themselves, and the state of the air between them. This distance,

whatever it happens to be between any two bodies, is called their

striking distance, as, till they come within that distance of each

other, no stroke will be made.



The clouds have often more of this fluid in proportion than the earth:

in which case, as soon as they come near enough, (that is, within the

striking distance,) or meet with a conductor, the fluid quits them and

strikes into the earth. A cloud fully charged with this fluid, if so

high as to be beyond the striking distance from the earth, passes

quietly without making noise or giving light, unless it meet with

other clouds that have less.



Tall trees and lofty buildings, as the towers and spires of churches,

become sometimes conductors between the clouds and the earth; but, not

being good ones, that is, not conveying the fluid freely, they are

often damaged.



Buildings that have their roofs covered with lead, or other metal, and

spouts of metal continued from the roof into the ground to carry off

the water, are never hurt by lightning, as, whenever it falls on such

a building, it passes in the metals and not in the walls.



When other buildings happen to be within the striking distance from

such clouds, the fluid passes in the walls, whether of wood, brick, or

stone, quitting the wall only when it can find better conductors near

them, as metal rods, bolts, and hinges of windows or doors, gilding on

wainscot, or frames of pictures, the silvering on the backs of

looking-glasses, the wires for bells, and the bodies of animals, so

containing watery fluids. And in passing through the house it follows

the direction of these conductors, taking as many in its way as can

assist in its passage, whether in a straight or crooked line, leaping

from one to the other, if not far distant from each other, only

rending the wall in the spaces where these partial good conductors are

too distant from each other.



An iron rod being placed on the outside of a building, from the

highest part continued down into the moist earth, in any direction,

straight or crooked, following the form of the roof or other parts of

the building, will receive the lightning at its upper end, attracting

it so as to prevent its striking any other part; and, affording it a

good conveyance into the earth, will prevent its damaging any part of

the building.



A small quantity of metal is found able to conduct a quantity of this

fluid. A wire no higher than a goose-quill has been known to conduct

(with safety to the building, as far as the wire was continued) a

quantity of lightning that did prodigious damage both above and below

it; and probably larger rods are not necessary, though it is common in

America to make them of half an inch, some three-quarters, or an inch,

diameter.



The rod may be fastened to the wall, chimney, &c., with staples of

iron. The lightning will not leave the rod (a good conductor) to pass

into the wall (a bad conductor) through those staples. It would

rather, if any were in the wall, pass out of it into the rod, to get

more readily by that conductor into the earth.



If the building be very large and extensive, two or more rods may be

placed in different parts, for greater security.



Small ragged parts of clouds, suspended in the air between the great

body of clouds and the earth, (like leaf gold in electrical

experiments,) often serve as partial conductors for the lightning,

which proceeds from one of them to another, and by their help comes

within the striking distance to the earth or a building. It therefore

strikes, through those conductors, a building that would otherwise be

out of the striking distance.



Long sharp points communicating with the earth, and presented to such

parts of clouds, drawing silently from them the fluid they are charged

with, they are then attracted to the cloud, and may leave the distance

so great as to be beyond the reach of striking.



It is therefore that we elevate the upper end of the rod, six or eight

feet above the highest part of the building, tapering it gradually to

a fine sharp point, which is gilt, to prevent its rusting.



Thus the pointed rod either presents a stroke from the cloud, or if a

stroke be made, conducts it to the earth, with safety to the building.



The lower end of the rod should enter the earth so deep as to come at

the moist part, perhaps two or three feet; and if bent when under the

surface, so as to go in a horizontal line six or eight feet from the

wall, and then bent again downwards three or four feet, it will

prevent damage to any of the stones of the foundation.



A person apprehensive of danger from lightning, happening during the

time of thunder to be in a house not so secured, will do well to avoid

sitting near the chimney, near a looking-glass, or any gilt pictures

or wainscot; the safest place is in the middle of the room, (so it be

not under a metal lustre suspended by a chain,) sitting in one chair

and laying the feet up in another. It is still safer to bring two or

three mattresses or beds into the middle of the room, and, folding

them up double, place the chair upon them; for they, not being so good

conductors as the walls, the lightning will not choose an interrupted

course through the air of the room and the bedding, when it can go

through a continued better conductor, the wall. But where it can be

had, a hammock or swinging-bed, suspended by silk cords equally

distant from the walls on every side, and from the ceiling and floor

above and below, affords the safest situation a person can have in any

room whatever; and what, indeed, may be deemed quite free from danger

of any stroke by lightning.





Writing On Glass By The Rays Of The Sun The Alteration As The A Into D The C Into A E D G O Or Q The I Into B D Or L The L Into T The O facebooktwittergoogle_plusredditpinterestlinkedinmail

Feedback