16 BULLETIN 744, U. S. DEPARTMENT OF AGRICULTURE. 
ground to the top of tank is required. If built entirely above the 
ground a complete outside form is necessary. After the outside 
forms are in place pour 4 inches of concrete in the bottom. On this 
concrete set the inside form, leaving a space of from 2 to 4 inches 
between the forms, depending on the thickness of the outside wall. 
After the concrete is set remove the inside form and coat the inside 
walls and floor with hot asphalt or tar. The sheets of insulation 
should be coated also with the same material and put in place on the 
floor and against the walls, care being taken to make all joints tight. 
After the insulation is in place cut down the inside form, previously 
used, to a size that will provide a 4-inch space between the walls and 
ye ae ale “yy ays Ze 
Fig. 12.—Arrangement of concrete-insulated cooling tank built partly below ground level. 
forms. The form should be set in place and blocked up 4 inches 
above the floor, and the concrete for the inner walls and floor should 
be poured in one operation. The wooden curb around the top of the 
tank should have 20-penny spikes driven into the underside at fre- 
quent intervals and the curb set in place and pressed down so as to 
embed the spikes in the concrete before it sets. If the inner surface 
of the walls is rough upon removal of the forms, a plaster coat of 
cement mortar should be applied. 
DIVIDING THE TANK INTO A SMALL AND A LARGE COMPARTMENT. 
The size of the tank depends upon the quantity of milk to be 
cooled. Frequently tanks are built of such sizes as to require an ex- 
