C U B 



Let.yz 



CORDS, strength of. (Gregory.) 



The best mode of estimating the strength of a cord of hemp is to mul- 

 tiply by 200 the square of its number of inches in girth, and the product 

 will express in pounds the practical strain it may be safely loaded with. 

 For cables, multiply by 120, instead of 200. The ultimate strain is pro- 

 bably double this. 



For the utmost strength that a cord will bear before it breaks, a good 

 estimate will be found by taking- -J. of the square of the girth of the cord, 

 to express the tons it will carry. This is about double the rule for prac- 

 tice just given ; and is, even for an ulterior measure, too great for tarred 

 cordage, which is always weaker than white. 



In cables, the strength when twisted, is to the strength when tho 

 fibres are parallel, as about 3 to 4. 



The following fa the breaking strain, l>y experiment, in the best bower ca- 

 bles at present employed in the British navy. (Encyc. Metrop.) 



From the experiments of Mr. LaMHardiere, it appears, that if we call 

 the strength of flux HHIO; that of the American aloe will be 50fi j of hemp 

 1390 ; of Now Zealand flax lift*. ; and of silk 289 i. f Young's Nat. Phil) 



COSINES,/#re of. See Fin 

 CUBATURES of Solids. See Solids. 

 CUBE Roots of Numbers. -Sec Involution. 

 00 



