Capillary Attraction. 347 



subtracting 



from h or 14,1544, we have 



h = 14,0397, 



which differs 0,4657 of a millimetre, or 0,0183 of an inch, from 457. 

 13,574, the observed altitude. 



460. If the plates are inclined to each other at a small angle, 

 the line of meeting being vertical, the water will rise between Figi2 25. 

 them to different heights according to the general law above 

 enunciated ; that is, the distances at L, G, being ZJV, G/, we 

 shall have 



GH : LM : : ZJV : GI : : M : HK. 

 But, by similar triangles, 



M O : H K : : FM : FH, 

 whence 



GH : LM :: FM : FH, 



that is, the heights at different points of the curve ELGB are 

 inversely as the distances from the line of meeting EF of the 

 plates. Therefore, since the relation of the lines FM, FH, &c., 

 to the lines LM, GH, &c., is the same as that of the abscissas 

 to the ordinates in the common hyperbola, the surface of the 

 fluid between the plates answers to this curve. 



461. If the relative attraction of the parts of the fluid for itself, 

 (in the case of tubes for example) and for the substance of the tube, F . ^^ 

 be such that the surface of the fluid column in the tube becomes 

 convex, instead of being concave, the effect is precisely the reverse 

 of that above considered ; that is, when an equilibrium occurs, 

 the filament occupying the axis of the tube and rising without the 

 tube to the free surface, will have its extremity/ 1 depressed ; since, 

 instead of an excess of upward attraction proceeding from a sus- 

 tained annulus, situated above a horizontal plane passing through 

 the extremity F, there will be a deficiency of upward attraction 

 equal to the effect of this same annulus. Accordingly, the de- 



