Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 2, 1802).djvu/537

Rh This machine was, in the year 1794, presented to the Society for the Encouragement of Arts, &c. by Mr., of Southwark, for which he was rewarded with a premium of 20 guineas.

Description of the Cut of Mr. 's Improved Machine for raising large weights.

A A, are the double handles of the winch.

B, represents the large toothed wheel, in which the pinion on the axis C works.

D, a ratchet-wheel.

E, the click, or pall, which falls into the teeth of the ratchet, and thus prevents the machine from running back, in case the weight should at any time overcome the power.

F, the rack, as appears in jacks of the common construction.

From a comparison of Mr. 's jack with those in common use, the former differs from the latter only in one respect; namely, that, in the improved machine, a pall, or chick, and ratchet, are applied in such a manner as to stop the machine in the case above mentioned, and thus to prevent those melancholy accidents which frequently occur, especially on board of ships engaged in action; when, from inattention, or neglect in fixing the hooks, or from any other cause, the common jacks fail: and, as the difference in its mechanism is not material, the improvement may be easily applied to the instruments already manufactured.  . See.  JACK-DAW, or Corvus monedula, L. a notorious bird, that is a native of Britain. It breeds in steeples, old castles, and on lofty rocks, where the females deposit five or six eggs.

The jack-daw is a gregarious bird, feeding on insects, seeds, and grain. It is equally mischievous in the fields as well as in the gardens, and is so prone to stealing, that it carries away more than is necessary for its subsistence. Hence various methods have been contrived for taking this depredratordepredator [sic]: one of the most effectual is that practised in some parts of England, and which is so ingenious, that it deserves to be more generally known.

A stake, about five feet long, is first driven firmly into the ground; the upper point is previously made so sharp that no bird can possibly settle on it. Within a foot of the top is bored a hole, three quarters of an inch in diameter, through which a stick is put, about eight inches in length. A horse-hair noose is next fixed to a thin wand made of hazel, which is passed through the hole: the remainder being left open beneath the transverse stick. The other end of the hazel rod is then introduced into another hole in the stake near the ground, where it is fastened. The stake should now be placed in a situation which is frequented by the bird in quest of food, when he will consequently be induced to alight on it; but, on finding the point too sharp, he will probably settle on the little transverse stick: as this sinks with his weight, his leg will be effectually secured in the noose.  JALAP, in medicine, the root of the Convolvulus Jalappa, L. an exotic species of.

This root is imported in transverse slices from Xalapa, in South America. The best pieces are  pact,