1921.] 
Birks.—Electric Power for Milking-plants. 
Ill 
As a result of these tests 2 h.p. motors have been installed on 
several similar and even larger plants with quite satisfactory results, 
and this size is now being standardized for milking-machine drives 
o o 
generally. 
When the number of machines connected to a reticulation system runs 
into thousands, as it will in many of the electric-power districts being 
formed, the reduction from 3 h.p. to 2 h.p. each will mean that current 
equivalent to many hundreds of horse-power will be available for other 
industrial purposes which would otherwise have to be reserved for the 
magnetizing or idle current of the unnecessarily large motors. 
The results of the tests taken are detailed in the table on next page, 
and the curves herewith give the distribution of the demand over the 
various months of the year. The tests were taken on five representative 
[Strange, photo. 
Electrically-driven Dairy at Sunnyside Hospital. 
milking-plants in Canterbury operating from the Lake Coleridge power- 
supply. A specially checked integrating wattmeter was used to measure 
the units taken, and kilovolt-amperes were determined from readings 
of standardized ammeter and voltmeter. The motors were all the same 
size, 3 h.p., but various kinds of milking-machines and auxiliaries were 
employed, which accounts for the difference in power demanded. Further, 
some consumers work methodically as against the inefficient methods 
of others ; for instance, plant D milks the largest number of cows (90), 
while plant C milks less than half as many (35), but D consumes 
only half as much powder as C—that is, 0-56 kw., as against 1-14 kw. 
The difference is due to the difference in arrangement of the plants. 
C uses all appliances for milking and separating simultaneously, while D 
uses the appliances alternately. In the case of E a pump was also in 
service, accounting for the still higher demand. 
It is probable that if more consideration were given to proper align¬ 
ment of machines and shafting, and solidity of foundations, a higher 
