. The Edinburgh new philosophical journal. Science. given in the Enclopecdia Britannica. 281 the weight of the whole elevated fluid is proportional to the ho- rizontal extent of the surface which causes its suspension. These assumptions appear to me inconsistent with all the ob- served properties either of solid or fluid matter. The first of them, indeed, accords exactly with the observed non-distur- bance of a fluid's surface, until a solid is brought into actual contact with it. But although the action of the solid has only an evanescent extent before contact, it does not therefore fol- low,
. The Edinburgh new philosophical journal. Science. given in the Enclopecdia Britannica. 281 the weight of the whole elevated fluid is proportional to the ho- rizontal extent of the surface which causes its suspension. These assumptions appear to me inconsistent with all the ob- served properties either of solid or fluid matter. The first of them, indeed, accords exactly with the observed non-distur- bance of a fluid's surface, until a solid is brought into actual contact with it. But although the action of the solid has only an evanescent extent before contact, it does not therefore fol- low, that after contact has taken place, its influence is not sen- sibly extended ; neither can such a supposition be admissible when it leads us to conclude, that a mass of matter is elevated and sustained by a force applied only at one extremity, and which, therefore, does not pass through its centre of gravity. The subject is one of great importance, and I imagine that a scrutiny of the reasoning may not be unacceptable. In con- ducting this examination, I shall first demonstrate the inade- quacy of the hypothesis to account for the phenomena, and then attempt to indicate that error which has led the cele- brated author of the above-mentioned paper to a conclusion ex- actly opposite. Let AB represent the vertical face of a solid partially immersed in a fluid whose horizontal surface is CM, its disturbed surface MLK. Having traced a canal vertically from C to D, thence horizontally to P, and after- wards vertically upwards, to termi- nate in the disturbed surface at L, it is obvious, that the equilibrium of the fluid contained in this or any other canal, is essential to that of the whole mass. Now the horizontal portion DP is already in equilibrium with respect to all the attractions acting upon itself, since the attraction of the plate is not supposed to ex- tend so far, and it may therefore be regarded as the mean of communication between the two vertical branches CD and LP; th
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