Endless Amusement: A Collection of Nearly 400 Entertaining Experiments in Various Branches of Science; Including Acoustics, Electricity, Magnetism, Arithmetic, Hydraulics, Mechanics, Chemistry, Hydrostatics, Optics; Wonders of the Air-Pump; All the Popular Tricks and Changes of the Cards, &c., &c. to Which is Added, a Complete System of Pyrotechny; Or, the Art of Making Fire-works.Unknown
Science
Endless Amusement: A Collection of Nearly 400 Entertaining Experiments in Various Branches of Science; Including Acoustics, Electricity, Magnetism, Arithmetic, Hydraulics, Mechanics, Chemistry, Hydrostatics, Optics; Wonders of the Air-Pump; All the Popular Tricks and Changes of the Cards, &c., &c. to Which is Added, a Complete System of Pyrotechny; Or, the Art of Making Fire-works.
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.
_The Leech, a Prognosticator of the Weather._
Confine a leech in a large phial, three parts filled with rain water,
regularly changed twice a week, and placed on a window frame, fronting
the north. In fair and frosty weather it lies motionless, and rolled
up in a spiral form, at the bottom of the glass: but prior to rain or
snow, it creeps up to the top, where if the rain will be heavy and of
some continuance, it remains a considerable time; if trifling, it
quickly descends. Should the rain or snow be accompanied with wind, it
darts about its habitation with amazing celerity, and seldom ceases
until it begins to blow hard. If a storm of thunder or lightning be
approaching, it is exceedingly agitated, and expresses its feelings in
violent convulsive starts, at the top of the glass. It is remarkable
that however fine and serene the weather may be, and not the least
indication to change, either from the sky, the barometer, or any other
cause whatsoever, yet, if the animal ever shift its position, or move
in a desultory manner, so certain will the coincident results occur,
within thirty-six hours, frequently within twenty-four, and sometimes
in twelve; though its motions chiefly depend on the fall and duration
of the wet, and the strength of the wind.
_The Awn of Barley an Hydrometer._
Public-domain text, read in full here on John Shaqi.
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