In two corks, A and B, insert four wing-feathers from any bird, so as to
be slightly inclined, like the sails of a windmill, but in opposite
directions to each set. A round shaft is fixed in the cork A, which ends
in a sharp point. At the upper part of the cork B is fixed a whalebone
bow, having a small pivot-hole in its centre, to receive the point of
the shaft. The bow is then to be strung equally on each side to the
upper portion of the shaft, and the little machine is completed. Wind up
the string by turning the bow, so that the spring of the bow may unwind
the corks, with their anterior edges ascending; then place the cork,
with the bow attached to it, upon a table, and with a finger pressed on
the upper cork, press strongly enough to prevent the string from
unwinding, and taking it away suddenly, the instrument will rise to the
ceiling.—Dr. Piesse.
[Illustration: Fig. 151.]