It should be thoroughly understood by all that any common paper, coarse
wrapping paper, new or old newspapers, etc., are admirable to keep out
cold or keep in warmth. The blood of _all_ domestic animals, as well as
of human beings, _must_ be always kept very near 98 degrees, just as
much in winter as in summer. And this heat always comes from _within_
the body, whenever the atmosphere is not above 98 degrees temperature.
So long as the air is cooler than this, the heat produced inside the
body is escaping. Heat seeks a level. If there is more in one of two
bodies or substances side by side, the heat will pass from the warmer
into the colder, until they are both of the same temperature.
Moving air carries away vastly more heat than still air. The thin film
of air next to the body soon gets warm from it. But if that air is moved
along, slowly or swiftly, by a breeze, be it ever so gentle, new cooler
air takes its place, and abstracts more heat from the body. Anything
that keeps the air next to the bodies of men and of animals from moving,
checks the escape of heat.
The thinnest paper serves to keep the air quiet. A newspaper laid on a
bed acts much as a coverlid to keep a film or layer of air quiet, and
thus less heat escapes from the bodies of the sleepers. If paper is
pasted up over the cracks of a house, or of a barn or stable, or under
the joists of a house floor, it has just the same effect. Every person
who keeps animals will find it a wonderful and paying protection to
them, to put against the walls one, two, three, or more layers of
newspapers during cold weather. If a person in riding finds his garments
too cool, a newspaper placed under the coat or vest, or under or over
the trousers, even if only on the side next the wind, will do a great
deal to check the outflow of heat, and keep him warm. Two or three
thicknesses of newspaper crumpled a little, and put under the coat or
overcoat, are almost as effective in keeping in warmth as an extra
garment. A slight crumpling keeps them a little separate, and makes
additional thin layers of air.
Further: Heat does not pass through films of _still_ air. Fibrous
woolens, furs, loosely woven cotton, down, and the like, contain a great
deal of air _confined_ in the meshes, and are therefore excellent
conservers of heat. Double walls of stone, brick, or wood, or even of
wall or roofing paper, double glass, double layers of anything that will
have thin layers of still air between them, prevent the escape of heat
greatly.
* * * * *