4 BULLETIX 57, U. S. DEPARTMENT OF AGRICULTURE. 
earth or sand and lay the concrete and reenforcing on this cone, 
Allow it to set and harden well before removing the forms and earth. 
The following table gives an approximate bill of materials for two 
sizes of cisterns: 
C is ter ns- — Ma Una I . 
[Concrete: 1 part cement, 2\ parts sand, 5 parts gravel.] 
14 feet 
13» feet 
deep 
deep 
(10-foot 
(10-foot 
cylinder, 
evlinder, 
4-foot 
3Woot 
Material. 
cone), 
cone), 
8 feet in 
6 feet in 
diameter, 
diameter, 
capacity 
capacity 
3,800 
gallons. 
2,100 
gallons. 
Cement bags. . 
Sand cubic yards. . 
Gravel do 
Brick for filter wall 
Lumber for forms board feet. . 
1.000 
22.5 
31 
800 
200 
The Office of Public Roads of this department has established a 
method of makhig concrete by intermixhig mineral residuum oil, 
Fig. 2.— Crib of brick or stone for intake from pond. 
which, according to then tests, makes a damp-proof and fairly 
water-tight concrete. Information may be obtained by writing to 
that office for their bulletin on oil-mixed Portland cement concrete. 1 
If water is piped from a stream or pond subject to pollution, the 
pipe entrance should be placed hi a crib and screened, as shown in 
figure 2. The pipe can then empty into a receiving filter, made of 
concrete, which contains fine sand, gravel, and powdered charcoal 
in layers (fig. 3), and from which it empties mto the cistern. The 
ram-water pipe from the eave trough should be provided with a 
switch or cut-off, so that the flow may be diverted to the outside — 
as, for instance, for a short time at the beginning of rains — to exclude 
the filth collected on the roof and gutters. An overflow pipe should 
be provided in the side of the cistern and should be screened to 
exclude rats and other vermin. 
U. S. Dept. Agr., Office Pub. Roads Bui. 46. 
