[3]proveth.
[A Tobacco-tongs Engine.] The designation here given, when published in 1663, was doubtless generally understood, but the smallness of the “engine,” its very nature, and not less, its long discontinuance of use, now renders the passage obscure. It so happens, however, that a scientific experiment, in which this humble instrument was employed by the Honourable Robert Boyle, has preserved, for our information in this matter, the true figure of the “tobacco-tongs.” In the 3rd Volume of Boyle’s Works, folio, published in 1744, is recorded his pneumatical experiments on the falling of bodies in vacuo. Treating of “New experiments physico-mechanical, touching the spring of the air,” illustrated by the well-known experiment of dropping at the same time a guinea and a feather within an exhausted glass receiver, he says: “We so fastened a small pair of tobacco-tongs to the inside of the receiver’s brass cover, that by moving a turning key, we might by a string tied to one part of them open the tongs, which else their own spring would keep shut.”
In an illustrative engraved plate, accompanying his description, the fourth figure therein is designed to show the “tobacco-tongs,” which appear in the form of a figure of 8, as in the annexed diagram, where a, is the top or hand portion, being the largest oval, while the lower oval b, is not above one third its size, at which point this steel spring instrument was cut through, to form the tong or nippers. We imagine that a side view would be like the dotted figure c, d, where d, shows how the ends of these nippers were probably elongated a little, the more readily to take up and part with the tobacco or other material. The least pressure on the outside of the large oval, will extend the nippers b, d, which again close when such pressure is removed.
But there may have been another form of such tongs, like the letter X, or two such figures combined; and by increasing the series we should produce the instrument known as the lazy-tongs, which collapse into a very small space, yet will extend to a great distance.
50.
A complete light portable Ladder, which taken out of ones Pocket, may be by himself fastened an hundred foot[4] high to get up by from the ground.
Footnote
[4]feet. P.
[A Pocket-ladder.] There are many curious and ingenious designs for portable scaling ladders, offered by Vegetius in “De re militari,” 1535, but which would require to be very considerably modified to become pocketable; however, they occur in every variety at page 35, in short pieces, each with a screw at one end, and a socket at the other; at p. 59, as a neat rope ladder; at p. 113, on the principle of the lazy-tongs; and at p. 162, a method of connecting short poles is exhibited.