satisfactory. For desserts of this kind, a vacuum freezer, that is, one
that requires no turning, may be used.

In such a freezer a container extends down through the center of the can
and is surrounded by an air space. The mixture to be frozen is poured
into this container from the top and the ice-and-salt mixture that does
the freezing is put in from the bottom and takes up the air space.
Covers fasten securely both the top and the bottom. A handle attached to
one side makes the handling of such a freezer an easy matter.

By many, a freezer of this kind is considered a decided advantage over
the usual variety of freezer, for it requires no turning, but there are
certain disadvantages about its use that should be understood before one
is secured. In the first place, the expansion that is produced in the
mixture by the incorporation of air when an ordinary freezer is used
does not occur in a vacuum freezer. Also, the texture of the finished
product is not, as a rule, equal to that of the dessert made in a
freezer turned with a dasher. In addition, it is necessary to crack the
ice somewhat finer for a vacuum freezer and to mix it thoroughly with
the correct proportion of salt required for the particular kind of
mixture frozen.

[Illustration: FIG. 16]

[Illustration: FIG. 17]

[Illustration: FIG. 18]

69. When a vacuum freezer is to be used, turn it upside down and insert
the ice-and-salt mixture through the opening in the bottom. Then close