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to this turpentine and drier also should be added. White lead is 
used everywhere, but tends to yellow somewhat in the dark. White 
zinc is used chiefly on interior work, being the whitest paint known. 
Colored paints are commonly made by adding colored pigments to 
lead or zinc. White, light blue, and light green are less durable 
than yellow, gray, or dark colors. 
Painting always should be done in dry weather, and paint should 
not be applied to lumber that is not dry. A week or more should 
be allowed to elapse between successive coats. A gallon of paint 
will cover from 400 to 600 square feet of surface, depending upon 
the character of the surface. 
WHITEWASH. 
Ordinary whitewash is made by slaking quicklime in water in a 
pail or barrel covered with cloth or burlap. The proportions of lime 
and water should be about 10 pounds of the former to 2 gallons of 
the latter, and the lime should be allowed to slake for one hour. 
When the slaking is complete, enough water should be added to 
bring the whitewash to a consistency which may be applied readily. 
Weatherproof whitewash for exterior surfaces may be made as 
follows : 
(1) Slake 1 bushel of quicklime in 12 gallons of hot water; (2) 
dissolve 2 pounds of common salt and 1 pound of sulphate of zinc 
in 2 gallons of boiling water; (3) pour (2) into (1), add 2 gallons of 
skim milk, and mix thoroughly. 
Roofing Materials, 
prepared roofing. 
There are on the market a large number of so-called " prepared" 
or " ready" roofings for covering the sheathing of wooden roofs. 
They are made by cementing together two, three, or more layers of 
tar-saturated felt or felt and burlap, then coating the combination 
either with a hard solution of the same cementing material or with 
a mixture of hot pitch or asphalt and sand or fine gravel. These 
roofings are commonly put up in rolls 36 inches wide and are applied 
by lapping the strips 2 inches, with a coat of cementing material 
between, and nailing every 2 or 3 inches with tin-capped roofing 
nails. A sufficient quantity of cement, nails, and tin caps is packed 
in the middle of the rolls. These roofings are especially suitable 
for use in convict camps, for the reason that no previous experience 
is required for laying them. 
In the construction of the portable buildings previously described 
the prepared roofing can be fastened to the roof sections very satis- 
factorily with No. 9 flaked glue. 
