fixed the handle C, which supports the frame D, about 12
inches high, and four inches wide. This frame is to be covered with
oiled paper, and divided into 12 equal parts by horizontal lines, at
the end of which are written the numbers for the hours, from 1 to 12,
and between the horizontal lines, and diagonals, divided into halves,
quarters, &c. On the handle C, and close to the glass, is fixed the
style or hand E.

[Illustration: Fig. 4.]

Now, as the distance of the style from the flame of the lamp is only
half an inch, then, if the distance of the frame from the style be six
inches, while the float that contains the light descends by the
decrease on the oil, one inch, the shadow of the style of the frame
will ascend 12 inches, being its whole length, and show by its
progression, the regular increase of the hours, with their several
divisions.

You must be careful always to burn the same oil, which must be the
best; and the wick must never vary in size; if these precautions are
not attended to, the dial never can be accurate.

_The Phial of the Four Elements._

Take a phial, six or seven inches long, and about three quarters of an
inch in diameter. In this phial put, first, glass coarsely powdered;
secondly, oil of tartar per deliquum; thirdly, tincture of salt of
tartar; and lastly, distilled rock oil.

The glass and the various liquors being of different densities, if you
shake the phial, and then let it rest a few moments, the three liquors
will entirely separate, and each assume its place; thus forming no
indifferent resemblance of the four elements, earth, fire, water, and
air: the powdered glass (which should be of some dark colour)
representing the earth; the oil of tartar, water; the tincture, air;
and the rock oil, fire.

_The Magic Bottle._

Take a small bottle, the neck of which is not more than the sixth of
an inch in diameter. With a funnel, fill the bottle quite full of red
wine, and place it in a glass vessel, similar to a show-glass, whose
height exceeds that of the bottle about two inches; fill this vessel
with water. The wine will shortly come out of the bottle, and rise in
the form of a small column to the surface of the water; while at the
same time, the water, entering the bottle, will supply the place of
the wine. The reason of this is, that as water is specifically heavier
than wine, it must hold the lower place, while the other rises to the
top.

An effect equally pleasing will