E Q U 



Cubes of different metals of ^ inch were crushed by the following 

 weights : 



Cast Iron 



Cast Copper *~~~ 



Fine Yellow Brass 



Ibs. av. 

 9773 

 7318 



10304 



Wrought Copper * 

 Cast Tin -- 

 Cast Lead , 



Ibs. av. 

 6440 



483 



Bars of different metals six inches long 1 , and ^ inch square, were sus- 

 pended by nippers, and broken by the following weights : 

 Ibs. av. 

 1166 

 1218 



Ibs. av, 

 2273 

 2112 

 1192 

 1123 

 296 



Cast Iron, horizontal ~~ 1166 Gun Metal 



Ditto, vertical <..~..~.~ 1218 Copper hammered 



Cast Steel ~~~,~~ -~~ 8391 Cast Copper 



Blistered Steel hammered 8322 Fine Yellow Brass 



Shear Steel do 7977 Cast Tin 



Swedish Iron do. ~~ 4504 Cast Lead r*~~~~~> \\k 



English Iron do. ~~* 3492 



ELASTIC bodies, theory of.^-See Collision. 

 ELLIPSE, principal properties of. See Conic Sections. 

 ELLIPTICITY of the Earth. See Earth, figure of. 

 EMBANKMENT. See Dyke, and Earth pressure of. 

 EPOCH. See JEra. 

 EQUATIONS of condition. (flay fair, Maddy.) 



Any equation expressing the relation that obtains among the coem. 

 cients of another equation, is called an Equation of condition. These 

 equations are used in determining by observation the constant coefficient* 

 in an assumed or given function of a variable quantity. Thus let us sup- 

 pose that the form of the function is known from theory, but that the 

 onstant quantities that enter into it, are to be determined by observe 

 102 



