COL 



JS ,r -f- C y -f- D ~ n, where the coefficients of .vs and y>. are the same, 

 and the term involving x y is wanting 1 , is an equation to the circle ; as 

 for example 2 y a -|- 2.rg 1 y 4* x -f- 1 o. 



2. When the circle is considered as a spiral, Jet a distance of the 

 centre of the polar coordinates from the centre of the circle, y = rad. 

 vect. p perpendicular on the tangent j then 



When the pole is in the circumference, 



CISSOID of Diodes, Equations, 



Or, when considered as a spiral, 

 _ 2 a sin.a 5 



3 -r 2 

 Area = - 3 area of the generating semicircle. 



Content of solid jt f^-^-a ,f2 + 4 a8 x 8 as log. ^ - J 



which is infinite when x 2 a. 

 CLEFS YD RA.See F/wufe, discharge of. 

 CLIMATE. See Atmosphere. 

 CLOCK, #o correct going of. See Pendulum. 

 CLUSTERS of Stars. See Nebula. 

 COHESION, or Attraction of Cohesion. See Elastic Sadies, equilibri- 



um of. 



COINAGE. See Money. 

 COLD Artificial. See Frigorific Mixtures. 

 COLLISION of Bodies. ( Wood, WhewellJ 



I. Oftfie impact of perfectly hnrd bodies. 

 i. Let A and B be the quantities of matter contained in t\vo perfect I j- 



