4 BULLETIN 890, U. S. DEPARTMENT OF AGRICULTURE. 
12. Can washer. 
13. Labor-saving devices, as elevators and conveyers. 
14. Boilers, engines, refrigeration machinery, motors, hot-water heater, etc. 
15. Sanitary milk pumps and piping. 
16. Separator and churn. 
17. Cans, bottles, cases, etc. 
SCALES AND WEIGH CAN. 
At very small plants the milk can be weighed in the cans and the 
weigh tanks will not be needed. In all cases, whether milk is paid 
for by the gallon or by weight, it should be weighed. If milk is 
paid for by the gallon the weight can be readily converted to gal- 
lons ; in fact, there are scales on the market which record the quantity 
in gallons as well as pounds. One company handling a little more 
than 4,000 gallons of milk daily decided after several years to buy 
and sell the milk by weight. Scales were installed and the difference 
between the measure by the cans and the actual quantity of milk 
received, as shown by the scales, was determined. Table 2 shows the 
differences in a two-month test. 
Table 2. — Difference beticeen can measure and actual quantity of milk received 
as shotcn by scales, at a city plant. 
Items. 
First 
month. 
Second 
month. 
Gallons. 
126, 460 
124,331 
Gallons. 
138,485 
135,941 
Scale 
2,128 
2,544 
Thus, during April there was a difference of 2J28 gallons and in 
May 2,544 gallons. At this rate the plant paid for over 2,000 gallons 
of milk more than it actually received in each of the two months, or 
a difference of more than $600 a month, if milk is worth 30 cents a 
gallon. 
At another plant, where the milk was received by measure, 55 
10-gallon cans of milk were weighed, first weighing the full can 
and then weighing the empty can after it had drained on a drip pan. 
The lowest net weight for the can of milk was 80 pounds and the 
highest 85f pounds, or a variation of 5} pounds. The average of the 
55 cans was 83j pounds, or 2-j pounds less than the usually accepted 
weight for 10 gallons of milk. Only full cans were included, so the 
dealer actually lost 3.19 per cent. This dealer handled 2,000 gallons 
daily, and valuing the milk at 30 cents a gallon the daily discrepancy 
would be 63.8 gallons, or an overpayment of $19.14. The purchase 
