Chap. 5-] Old German Bellows Pump. 207
board has also an opening in its centre which is closed by a valve or clack,and also furnished with a rod and handle. The under board sometimesforms the bottom of a box, in one side of which a spout is inserted, asshown by the dotted lines.
The earliest representation of a bellows pump which we have metwith in books, is among the curious cuts attached to the first German translation of Vegetius , from which No. 82 is copied. (Erfurt 1511) a Itwill suffice to show the application of this kind of pump to raise waterat that time. There was of course a valve covering the interior orificeof the nozzle and opening outwards, to prevent the air from enteringwhen the upper board was raised. This valve is not shown because theart of representing the interior of machines by section, was not then un-derstood, or not practiced. The lower board is fastened to the ground bya post and key, and a weight is placed on the upper one to assist in ex-pelling the water.
fesf > i'-
One hundred years ago, two bellows fixed in a box and worked by adouble lever, like the old fire or garden engine, was devised by M. DuPuy, Master of Requests to the king of France . The machine was re-commended to raise water from the holds of ships, drain lands, &c. Itappears that the widow of M. Du Puy, expected to reap great advantagesfrom it in England; but Dr. Desaguliers , in 1744, published a descriptionof it taken from the French account, and among other remarks he ob-served—“About fourteen years ago, two men here applied for a patentfor this very engine, proposing thereby to drain mines * * * “ all thedifference was, that their bellows were fixed upon a little Waggon; andttiey had a short sucking pipe under; and the force pipe went up fromt’ne two bellows. I opposed the taking out of this patent, because Ithought it would be of great hurt to the undertakers, to lay out nearei ghty pounds for what would never bring them eighty pence ; unless theymade a bubble of it, and drew unwary people into a scheme to subscribemoney.” (Ex. Philos. ii, 501.) Bellows pumps were previously used inFrance . They are spoken of as common in the old Dict. de Trevoux.
indebted to John Allan, Esq. for a copy of this scarce old work. It is the sameo which Prof. Beckman refers in his-art.icle on the diving bell. Unfortunately the cutsare left without explanation.