EVA. 



If in the axis of the solid, or in the line passing through the two cen- 

 tres, there be taken a point distant from the centre of the immersed 



part by f g , this point is called the metacentre ; and $ie stability 



will be positive or negative or nothing, according as the metacentre is 

 above, below, or coincident with the centre of gravity of the floating 

 body. 



3. If a rectangular parallelepiped float in a fluid, with its altitude a 

 perpendicular to the surface ; if its breadth be 5, and its specific gravity 



n, that of the fluid being 1, its stability will be as w (1 w) a 8 . 



When it has no stability, w (1 w) a* zr 0, and a = -=> 



V6 n (1 w) 



/I W 



and n = | + V 3 . 



4 6 a* 



Cor. 1. When - ? is less than -7-, or when the height of the solid has 

 6 a 4 4 



a greater proportion to the base of the section than V!T : Vlf, two va- 

 lues may assigned to the specific gravity of the body, which will cause 

 it to float in the equilibrium of indifference. 



Cor. 2. If n = , as is nearly the case with fir, a = J v --r- 

 nearly. The truth of this conclusion may be shewn by experiment. 



EQUILIBRIUM of an Elastic Body See Elastic Bodies equilibrium 



of. 



EQUILIBRIUM of a Point. See Forces composition of* 



EQUINOXES, precession of. See Precession. 



ERRORS in Time, in Astronomy. See Time* 



EVAPORATION. 



Mean monthly evaporation from the surface of water, from the ex- 

 periments of Dr Dobson, of Liverpool, in the years n72, 1773, 1774 A and 

 1775. (Phil. Trans.) and Manchester Memoirs.) 



Inches. Inches 



January ..... ............. 1,50 July .......*....*.............. 5.11 



February 1.77 August 5.01 



March- 2.64 September 3.18 



April 3.30 October 2.51 



May 4.34 November 1.51 



June , mmmmfim ., mw , 4.41 December .,., 1.4& 

 109 G 



