]58 COHESION OF FLUIDS. 



angle requirecl. This semicircle moves sideway on two 

 hooks in staples, at each end of the bed. 



I, The tail or stem of the bed A, moving in a cylindrical 

 hole in the pillar, enabling the bed to be turned in any re- 

 quired direction, and which, with the movement F, enable? 

 the operator to place the shoe in any |X)sition necessary. 



K. The pillar, formed like the pillar oi a claw table, except- 

 ing fhe two side legs being in a direct line, and the other leg 

 at a right-angl-e with them. 



L. The semicircle II, shown separately, to explain how it is 

 connected with the staples, and how the notches are formecf. 



M. The tail or stem of the bed A, and the lower part of th« 

 bed N. shown separately, to explain hov/ the upper part of 

 the bed is raised or depressed occasionally. 



IX, 



Jn Essay on the Cohesion of Fluids. By Thomas Young, 

 M.D. Far. Sec. ii. 6V* 



(Concluded from 'page ^%.) 

 VII. Cohesive At tract ion of Solids and Fluids. 



ro?iesive at- w V E may therefore inquire into the conditions of equil^Lrium 



j>iH-,'!on of j^f jj^g ^\^^QQ forces acting on the angular particles, one in the 

 £.-.,■ H.s and ° = r ? ^ 



f-sids. direction of the surface of the fluid only, a second m that of 



tiie common surface of the solid and fluid, and the third in 

 that of the exposed surface of the solid. Now, supposing the 

 angle of the fluid to be obtuse, the whole super/icial cohesion 

 of the fluid being represented .by the radiu?, the part which 

 acts in the direction of the surface of the solid will bo propor- 

 tional to the cosine of the inclination ; and this force, added 

 to the force of the solid, will be, equal to the force of the com- 

 mon surface of the solid and flujd, or jto the differences of their 

 forces: consequently, the cosine added to twice the force of 

 the solid, will be equal to the whole force of the fluid, or to 

 the radius^i. hence the force of the solid is represented by half 



* Philos. Trans. 1805. 



tlie 



