[ 5^7 ] 



or ftiir more exadly thus: the hygrometer on the mountain being 

 heated eight degrees more (that is to 15*') will ftand at nearly 

 LXXV, for it is already heated to 7'', and by the third table 

 wants 2", 373 degrees of cold to bring it to C; but when heated 

 8® more, it will require 10,373 degrees of cold to bring it to C, 

 and, confequently, will mark nearly LXXV. Now, by the firft 

 table, LXXV at 15° Reaumur denote 7,205 of moifture, and 

 LXXX at 15° denote 8,045. 



■ Note — I regret much the want of Mr. Lefley's hygrometer (an 

 mftrument as fimple as it is ingenious) to compare its indications. 

 with thofe of Sauflure's. See 3d voK Nicholfon's Jour. 461. 



