which, being usually thin and light, has but little strength in itself,
probably less than that of a meat pie, while, by the shrinking of the
fruit in baking it is left unsupported: and it further serves, not
indeed as some good ladies seem to suppose, to increase the quantity of
juice, but to keep a portion of it in reserve; so that the pie may not
become too dry when a few spoonfuls of its more liquid contents have
been taken out. {175} This, I conceive, it effects in the following
manner. It contains, when inserted, a considerable quantity of cold air.
This expands as the pie is heated in the oven, until it drives out from
under the cup all, or nearly all, of the fluid that has originally
collected under it; and then, continuing to expand, much of the air
escapes through the air-holes of the pie into the oven. As the pie
cools, the portion of air remaining under the cup, and which, while
heated, was sufficient to fill it, contracts; and then the pressure of
the external atmosphere, entering through the air-holes of the pie, and
acting upon the surface of the juice round about the cup, forces a
portion of it into the cup, just on the same principle that water rises
into the chamber or cylinder of a pump when a partial vacuum is formed
in it. Having once risen into the cup, the same law of hydrostatic
pressure keeps it there until the cup is raised sufficiently to admit
air under its edge, when the juice of course escapes.

J.T.S.


_Curfew_ (Vol. ii., p. 103.).--Your correspondent Naboc will find the
information he seeks upon this subject in a valuable communication to
the _Journal of the British Archæological Association_, vol. iv. p. 133,
by Mr. Syer Cuming. To Mr. C.'s list may be added, Charter House,
London; Newport, S.W.; and Lowestoft, Suffolk.