Prior to the year 1890 cold storage was dependent upon the employment
of ice, but in the evolution of the cold-storage warehouse ice is no
longer a requisite. In fact, the temperature obtained by the
employment of ice precluded a thermometric register much below the
freezing point. The accepted temperature for butter and eggs was
formerly 40° to 50°; but through the introduction of mechanical
refrigeration, which has revolutionised the business economically as
well as physically, eggs now are held in storage at a temperature of
31° and butter from 10° to 18°. Under the former method of ice
storage, goods that were offered on the market as "held goods"--that
is, as coming from a cold storage--always brought several cents under
the prices of fresh merchandise. But the remarkable modern methods of
cold storage permit the carrying of dairy products for a number of
months and their successful sale afterward in competition with fresh
goods. Eggs stored in March are taken out in the following November
and have commanded as high and often higher prices than the fresh
commodity. Eggs have been kept two years and found perfectly sweet
when used. In freezing poultry and fish the temperature now frequently
given is zero and under. Poultry does not carry so well as other
merchandise. Although it is possible to keep it for two years, yet it
loses its flavour. Five or six months' storage is its usual average
limit.
Certain temperatures are maintained in the various compartments of a
cold-storage warehouse according to the requirements of the products,
and these temperatures are made possible by forcing through pipes
arranged around each compartment a brine composed of about ninety-five
per cent. of pure salt whose temperature has been reduced by the
action of the chemicals. When a shipper stores his goods there is an
implied contract with the storage company that the temperature
required for the product will be furnished and maintained. Failure to
do this renders the company liable for any damage to property. So
vital is this feature of the business, which is really the only
liability assumed by the company, that the custom prevails of taking
the temperature of each room as often as five times in every
twenty-four hours, and keeping the record in temperature books open to
the inspection of the shippers. A room filled with merchandise may not
vary in temperature one degree in six months.