Show tic the fotr tho amount of bisol inzitare ture present or the bo humidity of the air Is I 1 determined by I 1 a compi com parloa ldson of dry and nd wet bulb thermometer they are both ordinary bat but the bulb of the latter Is covered with that it is wet wel in tho the latest form t f instrument the tb thermometer mo Ino meter meters are mounted ou on ana arms carried by A abaft that is I 1 rotated by a crank which ia is geared to the abaft the too motion of the haft abaft rotates the tep ia in Voi planes and causes tho the water in tha the muslin to evaporate more or less 1 rapidly according accordi ox to the amount of in the air This evaporation lower lowers the too per raton of the this then ter eter and from table tables constructed after lone long experiment experiments the degree of mola tuyet faa an be I 1 determined by the difference in temperature between the two thermos therin om eten eters X J prindle in popular science |