802 IOWA DEPARTMENT OF AGRICULTURE 
chants. Laws of this kind would not greatly inconvenience the farmer, 
as most every farmer has lots of water and the majority of them have 
windmills. Take the little shotgun cans that we used with the Cooly 
system, which was one of the best systems for caring for cream that we 
ever had, and immerse these cans in a little tank of water where the water 
may run from it to the big tank, and you will have an ideal place for 
keeping cream. The cream should not be placed in the large cans until 
the day of shipment. I am satisfied that under these conditions, cream 
could be kept two or three days in most any kind of weather and be 
delivered in good condition. 
If I owned a dairy farm, I would certainly have a gasoline engine for 
operating my separator. I would have a milk house near enough to my 
residence so it would be convenient to have an abundant supply of hot 
water for cleansing the separator and all dairy utensils. I would have a 
well in the milk house and operate the pump with a gasoline engine, and 
also have my tank of cold water for caring for my cream. Some of you 
may think this would be a great expense, but I maintain that it would be 
a question of economy. I have a friend, Mr. Rockwell, of Belle Plaine, 
Iowa, who has a one and one-half horse power Fairbanks gasoline engine 
that cost him, I believe, $140 (and I presume it is unnecessary for me to 
say that I have no interest in any make of gasoline engines). This 
engine has been in constant use for six or seven years, with practically 
no expense. They have a herd of 20 Jersey cows and it costs him, on an 
average, 55 cents per month for skimming the milk twice a day from 
that herd of 20 cows, a little less than one cent each skimming. No man 
could skim that milk by hand for that price, if he put any value on his 
time. Outside of the question of labor, you will get a more exhaustive 
skimming, as the separator is run at a uniform speed. In connection 
with this, if the inflow of milk is kept the same, you get cream of about 
the same density from day to day, thus avoiding the annoyance of varia- 
tion of tests, which is one of our most common complaints. 
(Mr. Rockwell's Letter.) 
"Prof. G. L. McKay, 
Chicago, 111. 
Dear Professor : In regard to the cost of running our No. 5 U. S. 
cream separator would say: For running separator alone, it takes five 
gallons of gasoline a month at 11 cents per gallon, separating the milk 
from 20 cows; power 1% horse. When we run the churn and washing 
machine it takes from eight to ten gallons per month. We have sawed 
wood, shelled corn and always run the grind stone when needed. The cost 
of the engine is $140 with electric sparker, which is the cheapest way of 
running a small engine, doing away with electric batteries altogether, as 
the engine will start from the sparker. If I can be of any more help to 
you, call upon me. 
Yours very truly, 
Chas, H. Rockwell." 
Now, I have tested skimmed milk caught from the separator as it is 
separated on the farm under ordinary conditions, and I have found in 
some cases the fat in the skimmed milk to actually read over one per 
