Copyright
D. Peirce.

Observer and record of agriculture, Science and art (Volume v.1) online

. (page 17 of 35)
Online LibraryD. PeirceObserver and record of agriculture, Science and art (Volume v.1) → online text (page 17 of 35)
Font size
QR-code for this ebook


cising his own discretion in regulating the
quantities. It is safest to err on the side
of the white lead, as the durability of the
cement is no way injured by it, only a
longer time is required for it to dry and
harden. When the fittings will not ad-
mit easily of so thick a substance as flan-
nel being interposed, linen may be substi-
tuted, or even paper or thin pasteboard.

This cement answers well also for join-
ing broken stones, however large. Cis-
terns built of square stones, put together
with this cement, will never leak, or want
any repairs. In this case the stones need
not be entirely bedded in it; an inch, or
even less, of the edges that lie next the
water, need only be so treated; the rest of
the joint may be filled with good lime.

Another Cement that will stand the
action of boiling water or steam. — This
cement, which is preferable even to the
former for steam engines, is prepared as
follows: Take two ounces of sal ammoni-
ac, one ounce of flowers of sulphur, and
sixteen ounces of cast iron filings, or bor-



I.———

I ings, mix all well together by rubbing
them in a mortar, and keep the powder
dry.

When the cement is wanted for use
take one part of the above powder and
twenty parts of clean iron borings or
filings, and blend them intimately by
grinding them in a mortar.

Wet the compound with water, and
when brought to a convenient consistence,
apply it to the joint with a wooden or
blunt spatula. By a phiy of aftinities,
which those who are at all acquainted
with chemistry will be at no loss to com-
prehend, a degree of action and re-action
takes place among the ingredients, and
between them and the iron surfaces, which
at last causes the whole to unite as one
mass.

In fact, after a time, the mixture and the
surfaces of the flanches become species of
pyrites, holding a very large j)roportion
of iron, all the parts of which cohere
strongly together.

Blood Cement. — A cement often used
by coppersmiths to lay over the rivets and
edges of the sheets of copper in large boil-
ers, to serve as an additional security to
the joinings, and to secure cocks,



Online LibraryD. PeirceObserver and record of agriculture, Science and art (Volume v.1) → online text (page 17 of 35)