19 
in the process of every batch and the cans marked with date 
and number of batch, just as they come out of the sterilizer, 
so that later, if any fault comes to light, the causes may be 
traced back. The keeping and testing in a heated room is 
particularly important for all kinds of condensed milk, for 
goods destined to go to warm climates or that have to cross 
‘the equator on transit. 
The above are only the main features of the processes. 
In detail they are naturally very much varied. Superheating 
by blowing steam into the milk directly after condensation is 
practiced by some manufacturers and for special purposes, 
especially in the case of bulk milks. Machinery, pumps, 
seales, pipes, refrigerating and cooling devices and testing 
apparatus as well as the general arrangement of factories 
vary much, and undergo constant improvement, especially 
from the points of view of sanitation and saving labor. The 
filling of the cans is done by machinery. The capping and 
sealing of the cans was formerly all done by hand soldering by 
girls, but is now mostly done by soldering machines, especially 
since the introduction of vent-hole filling devices. a 
ee 
Large concerns usually manufacture their own cans 
‘either it: a tinshop connected with each plant or in a central 
factory from which they are distributed to the individual 
plants. 
A new device of recent date which will probably modify 
the process somewhat is the continuous concentrator. This is 
‘a machine by which milk can’ be concentrated in a continuous 
stream and the ratio of concentration regulated by regulating 
tke inflow of milk. It is not certain yet to what extent this 
‘machine is destined to replace the vacuum pan. The concen- 
trator may find application where plain unsweetened con- 
densed milk or skim-milk is made as a side line in large cream- 
cries, eoncentrating plants for confectioners, etc. But large 
concerns are likely to continue with the vacuum condensation, 
which eannot well be. displaced, especially for sweetened con- 
densed milk, on account of the addition of sugar. 
Condensed and evaporated milks are packed and marketed 
‘In cans of various sizes: 1 gallon, 20, 16, 15, 14, 12, 10 and 8 
ounce cans. These are packed in cases holding from six to 
ninety-six cans.. 
