278 BUTTER-MAKING. 
will not coo) the room as effectively as ice, but in the absence 
of ice this is better than no cooling at all. 
Cost of Producing One Pound of Butter.—The cost of pro- 
ducing a pound of butter varies at different creameries. Up 
to a certain limit, the more butter that is being produced at 
yy 
Dead Air Space 
Row of Tile Outlets 
Fig. 167.—Cross-section of a sewage-disposal tank. (Wallace’s Farmer.) 
one place the less will be the cost of production, that is, pro- 
viding the creameries are otherwise equally well managed. 
The Iowa State Dairy Commissioner has investigated this 
Ground Line 
Vent 
= 
m 
Waste Water from Cream Vats and Starter Can 
=> 
ae | f 
] 9 Manhole 
=) 
I 2 | 
é 
£ 
| 4\|I 
A°* (=) rd 
Fie. 168.—Septic tank for creamery sewage disposal. (By Prof. J. Michels.) 
The tank should be located in the ground with the top within a foot or 
two of the surface. It may be constructed of planks. Brick, stone, or 
concrete is preferable for durability. The tank should be built air- 
tight except in two places, D and E. 
> 
ry 
& 
6 
ry 
o 
\ Discharge: 
question and finds that the cost of production varies from 
1.2 cents to 6 cents per pound. According to the reports sub- 
mitted to the office of the State Dairy Commissioner, the 
highest cost of production comes from a co-operative creamery 
that makes a little less than 30,000 pounds of butter per year. 
The lowest cost of production is submitted by a co-operative 
