[ 426 ] 



figures of the log. of a number one-tenth lower, the remainder 

 thus found gives fathoms, and the refidue, decimal parts of fa- 

 thoms. 



Fathoms multiplied into 6 give feet, and multiplied into 72 

 give inches. The fathoms, feet, and inches are paralelipipeds, 

 which, for the purpofe of finding their weight, I fuppofe to ftand 

 on a bafis of one fquare inch ; confequently the inches are cubic 

 inches, of which 1728 make one cubic foot, as do 144 of thefe alti- 

 tudinal paralelipipeds, feet ; and fo do 24 of thefe paralelipiped 

 fathoms. All this is commonly known, but is proper to mention 

 here for greater clearnefs. That at the temperature of 32° the 

 difference of the logarithms gives the height of air in Englifh mea- 

 fure, has been fhewn by General Roy. Sir George Schuckburg 

 indeed fuppofes this to happen at the temperature of 31^,24, but 

 the difference is of no confequence. 



Though this fubjett is perfedlly elementary, yet fome examples 

 and the folution of a few problems will be ufeful to thofe that are 

 little accuftomed to it. In thefe I all along fuppofe the tempera- 

 ture conftant, namely, at 32^. 



Examples. 



