152

Chain Pump frorn Agricola.

[Book I.

became known as ‘■Paternoster pumps.’ For the same reason they arenamed Chapelet by the French , in common with the chain of pots.

No. 65. Chain Pump from Agricola.

The next author who describes these pumps, that has fallen in our way,is Bessern. Plate 50, of his ‘ Theatre Des Instrumens,’ is a representationof a double one. Two cylinders are placed parallel to each other, so thatthe chain passes through both. It is shown as worked by wind. A ver-tical shaft with sails is secured under the dome of an open tower; a cogwheel on the lower end of the shaft turns a trundle or pinion which is fix-ed on the horizontal axle of the drum, that carries the chain. Thus, whenthe wind turned the sails, water was raised through one of the cylinders,and when their motion was reversed by change of the wind, the liquid waselevated in the other. Tnstead of stuffed cushions, as in the precedingfigure, pistons, resembling somewhat those of fire engines, or forcingpumps, i. e. double cupped leathers are shown, (' Coquilles fond contrefand,’) the earliest instance of their use that we have met with. Besson,who appears to cla.im the addition of the second cylinder as an improve-ment of his own, was a French mathematician and mechanician, andspent a great part of his life in mechanical researches ; in the prose-cution of which he visited foreign countries. His ‘ Theatre’ containssuch devices as he collected abroad as well as those invented by himself.It was published at Lyons, with commentaries, after his decease, byBeroald, but the privilege to print was accorded to himself, ten years pre-vious to the date of its publicatior., i. e. in 1568. a

Kircher also figures the chain pump with two cylinders. The imper-fect mechanism and enormous friction of these old machines confinedtheir application to a limited extent in Europe during the 16th and 17thcenturies. Desaguliers left them unnoticed ; and at the time Switzerwrote (1729) they had been diseontinued in England. “I might (he ob-serves) from Bochler and others, have produced almost an infinite number

a Bayle, in his dictionary, says Beroald was twenty-two years of age when he publish-ed “some commentaries on the mechanics of James Besson; but he had scarce triedhis fortune that way, when he ran after the philsopher’s stone.”