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THE accidents that frequently happen, in ufing the Jack for raifing large weights, from the want of a contrivance to prevent the machine running back if the weight by any means overcomes the power, has long been obferved; but no attempts feem to have been made to protect the workmen on that occafion. Mr. Mocock, of Southwark, having produced a Jack, with a Click and Ratchet, fo contrived as to prevent that danger, the Society voted to him a bounty of TWENTY GUINEAS, he leaving a model with the Society for the use of the public.

On examining the annexed plate of Mr. Mocock's Jack, it will appear not to differ much, either in principle or conftruction, from thofe in common use; except that in this Jack a Pall, or Click and Ratchet, are applied in fuch manner as to hold the machine faft, if the weight

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overcomes the power, and thereby prevent any accident the workmen may be subject to, by the running down of the machine; by which the men are frequently exposed to danger, and often fuffer, especially on board ships in engagements; when, from inattention or neglect in fixing the hooks, or from any other caufe, the Jacks hitherto in ufe fail in the working.

Explanation of the Plate of Mr. Mocock's improved JACK FOR RAISING LARGE WEIGHTS.

A. A. The double handles of the winch.

B. The large-toothed wheel, in which the pinion on the axis (C) works.

D. A ratchet-wheel.

E. The click or pall, which, falling into the teeth of the ratchet, prevents the machine running back, if the weight overcomes the power.

F. The rack, as in common jacks.

A Jack for raising large weights, improved by M. Mocock.

Plate II.

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IT is with particular fatisfaction the Society obferve the progrefs making in the ufe of the Gun-Harpoon, in the Whale Fishery; which, as it was firft encouraged by them, has ever continued an object of their attention, and now promises to become annually of more general use. The following Certificates will further evince. the utility of that contrivance; and as the Fish taken were fhot at a diftance at which it would have been utterly impoffible to have secured them by the HandHarpoon, every one fo taken may be confidered as clear gain to the Nation.

The following Certificates having been received, the feveral Premiums, offered for Whales taken by means of the GunHarpoons, being THREE GUINEAS for each whale, were adjudged to the Harpooners under mentioned. N 3

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