A cook of good judgment by careful observation and comparison of
results, can soon learn to form quite a correct idea of the heat of her
oven by the length of time she can hold her hand inside it without
discomfort, but since much depends upon the construction of stoves and
the kind of fuel used, and since the degree of heat bearable will vary
with every hand that tries it, each person who depends upon this test
must make her own standard. When the heat of the oven is found to be too
great, it may be lessened by placing in it a dish of cold water.

_Boiling_ is the cooking of food in a boiling liquid. Water is the usual
medium employed for this purpose. When water is heated, as its
temperature is increased, minute bubbles of air which have been
dissolved by it are given off. As the temperature rises, bubbles of
steam will begin to form at the bottom of the vessel. At first these
will be condensed as they rise into the cooler water above, causing a
simmering sound; but as the heat increases, the bubbles will rise higher
and higher before collapsing, and in a short time will pass entirely
through the water, escaping from its surface, causing more or less
agitation, according to the rapidity with which they are formed. Water
boils when the bubbles thus rise to the surface, and steam is thrown
off. If the temperature is now tested, it will be found to be about 212°
F. When water begins to boil, it is impossible to increase its
temperature, as the steam carries off the heat as rapidly as it is
communicated to the water. The only way in which the temperature can be
raised, is by the confinement of the steam; but owing to its enormous
expansive force, this is not practicable with ordinary cooking utensils.
The mechanical action of the water is increased by rapid bubbling, but
not the heat; and to boil anything violently does not expedite the
cooking process, save that by the mechanical action of the water the
food is broken into smaller pieces, which are for this reason more