l wild beasts are tawny or fawn-coloured, or tabby,
or of some nondescript hue and pattern: if an animal were born with a
more decided colour, he would soon perish for want of ability to conceal
himself.

Warmth of different Materials.--"The indefatigable Rumford made an
elaborate series of experiments on the conductivity of the substances
used in clothing. His method was this:--A mercurial thermometer was
suspended in the axis of a cylindrical glass tube ending with a globe, in
such a manner that the centre of the bulb of the thermometer occupied the
centre of the globe; the space between the internal surface of the globe
and the bulb was filled with the substance whose conductive power was to
be determined; the instrument was then heated in boiling water, and
afterwards, being plunged into a freezing mixture of pounded ice and
salt, the times of cooling down 136 degrees Fahr. were noted. They are
recorded in the following table:--

Surrounded with -- Seconds.
Twisted silk.................................. 917
Fine lint..................................... 1032
Cotton wool.................................. 1046
Sheep's wool.................................. 1118
Taffety....................................... 1169
Raw silk...................................... 1264
Beaver's fur.................................. 1296
Eider down.................................... 1305
Hare's fur.................................... 1312
Wood ashes.................................... 927
Charcoal...................................... 937
Lamp-black.................................... 1117

Among the substances here examined, hare's fur offered the greatest
impediment to the transmission of the heat. The transmission of heat is
powerfully influenced by the mechanical state of the body through which
it passes. The raw and twisted silk of Rumford's table illustrate this"
(Prof. Tyndall on Heat.)

Waterproof Cloth.--Cloth is made partly waterproof by rubbing soap-suds
into it (on the wrong side), and working them well in: and when dry,
doing the same with a solution of alum; the soap is by this means
decomposed, and the oily part of it distributed among the fibres of the
cloth. (See "Tarpaulins.")

Incombustible Stuffs.--I extract the following paragraph from a
newspaper. Persons who make much use of musquito curtains, will be glad
to read it. "'The Repertoire de Chimie Pure et Appliquee' publishes the
fo