VELOCITY. 187 



TABLE, showing the weight of a cubic foot of different 

 substances. 



Avoir. 



1 cubic foot of Brass weighs 504 j Ib. 



" " Brick " 125 " 



" Copper " 555 " 



" u Clay " 135 " 



" " Coal (anthracite) " 54 " 



" " Coal (bituminous) " 50 " 



u " Granite " 165 " 



" " Iron (wrought) " 486} " 



" " Iron (cast) " 450| " 



" " Lead " 708} " 



" " Marble " 171 " 



" " Soil (common) " 124 " 



" " Sand 95 " 



" " Tallow " 59 " 



" " Water (pure) " 62J- " 



" u Water (sea) " 64J " 



" " Wood (oak) " 55 " 



" " Wood (yellow pine) " 42 " 



" " Wood (white pine) " 30 " 



" " Charcoal (hard wood) .... " 18 J " 



" " Charcoal (pine wood) .... " 18 " 



" " Cork . " 15 " 



VELOCITY.* 



The average velocities of different objects are found in 

 the following 



Parker's Philosophy. 



