First division, comprising Mechanics of fluids, and hydraulic architecture. (Gall. of practical sci.).

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1837 Excerpt: ...at diifferent points of their depths, may be very simply illustrated in the following manner: let K be a bag of leather, or some other tough and flexible material, filled with mercury, and attached to the extremity of a glass tube ii, in such a manner, that the mercury may just enter the tube when the bag is held in air. Then, if the bag be immersed in water, it is manifest that the pressure of the fluid will cause it to collapse, and the mercury will ascend in the tube to a certain height, corresponding to the pressure exerted by the water, at the depth where the bag is placed. If the bag continue to be lowered in the water, it will become more and more collapsed in consequence of the increased pressure, and the mercury will ascend higher and higher in the tube, and the heights to which it rises, will indicate the magnitude of pressure at different depths. Experiment 5. There is a very simple and amusing experiment, by which the propagation of pressure through fluids is illustrated, called the " Cartesian Devil," from M. Descartes, the celebrated French philosopher, by whom it was discovered; it is as follows. Let the little figure in the inverted jar Ab represent the " Cartesian Devil," surmounted by a bag-like crown of great size in proportion to his body, filled with some very light substance, such as air, and we shall therefore suppose that air is the body which it contains. The imp himself must be constructed of glass or enamel, so as to possess the same specific gravity as water, and therefore to remain suspended in the fluid. At the bottom of the vessel or jar, is placed a diaphragm or bladder, that can be pressed upwards by applying the finger to the extremity of a lever eo, moving round o as its fulcrum or centre of motion. The...