194 Milk and Its Products 
These slight differences in individual bowls are 
common to all of the different kinds of machines, so 
far as is known, and this being the case, it is al- 
ways due to the purchaser that he should secure from 
the manufacturer a guarantee that any given ma- 
chine will do work of a certain grade of efficiency. 
Other desirable. and undesirable features of a sepa- 
rator.—Other things being equal, that separator is the 
best which will skim clean at the lowest temperature 
and with the least number of revolutions per min- 
ute. Other details of construction being equally 
good, and the capacities being the same, that separator 
will run the easiest whose diameter is least. A ma- 
chine of small diameter not only runs easier, but is 
less easily thrown out of balance. The cream should 
be delivered in’ a smooth stream of uniform density, 
and the cream outlet should be of such form that 
a heavy cream may pass through it without danger 
of clogging. The bowl should be so constructed that 
all parts may be readily reached with the hand and 
thoroughly and easily cleaned. 
