isinglass, use common glue, which is much cheaper; and cover the whole
with spirit varnish, instead of balsam of Peru. This plaster cracks, and
has none of the balsamic smell by which the genuine court plaster is
distinguished. Another method of detecting the adulteration is to
moisten it with your tongue _on the side opposite to that which is
varnished_; and, if the plaster be genuine, it will adhere exceedingly
well. The adulterated plaster is too hard for this; it will not stick,
unless you moisten it on the varnished side.--_The Painter, Gilder, and
Varnisher's Companion_.

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AN IMPROVED HOISTING PULLEY WANTED.


A gentleman of this city has sent us the accompanying diagram of an
improved hoisting pulley, for which he say she would be willing to pay
any reasonable price provided he knew where to obtain it--the wheel, not
the price. It is a pulley within a pulley, the friction of the outer one
upon the inner one--the latter being held by a ratchet and pawl-acting
as a brake in lowering weights, while both would turn together in
elevating weights. The idea is rather an ingenious one, but we are
confident our inventors can attain a like object by simpler means.

[Illustration]

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