Show the ali meter the amount of moisture present or the tw of the air Is by a comparison compa comp titon arlson of dry and wet bulb they are both ordinary thermometer thermometers buethe but the bulb rt rf r t the latter IS i covered with that Is 1 wet in the latest form forra of instrument the ther dometer mo meter meters are mounted on arm arms carried by a abaft shaft that if is rotated by a crank crack which if to geared to the baft shaft th v no zoo if kioa of the baft shaft rotates the thermos a tn tars la in vertical planes and causes tho water in the mustin to evaporate more or lei less rapidly according to the amount of in theair the air this eval p orallous oral loss lower the temperature cf of the ther nirm 8 eter ter and from tables constructed after long experiment experiments the derree degree of moisture moi itaro can bo be determined by the difference in temperature between the tho two eter stem EJ prindle in popular science |