RECORD AND DISCUSSION OF TEMPERATURES. 



In order to test his thermometers, Dr. Kane provided himself with chemically 

 pure mercury, and noted the temperatures at which it became solid. The follow 

 ing notes have been extracted from the log : 



Nov. 25, 1853. The mercury was exposed upon the floe at the meteorological observatory, and remained 

 liquid with the spirit standard at 42.0. 



Dec. 8, 1853. At two o clock, the mercury exposed was found frozen at 40. 5 of the spirit standard, 

 the mercurial standard being at 39. 8. 



Dec. 14, 1853. The mercury froze around the edges of the saucer containing it; S at 41. 0, and M 

 at 40.0. 



Jan. 16, 1854. Mercury in bulb ceased to record at 43. 5 ; observed frozen at 38. 0. 



Jan. 29, 1854. The mercury in the standard instrument, after registering 43. 0, descended in the 

 bulb; at another time it registered, after being frozen, 44. 0, and then became sta 

 tionary. 



Nov. 29, 1854. Mercury congealed at 43,0 of spirit standard, and resumed its fluidity at 38.0. 



If we refer the readings of the spirit standard to those of the mercurial standard 

 by adding + 0.3, we obtain the following observed temperatures for the freezing 

 point of mercury : 



-40.2 39.8 40. 7 40.0 38.0 and 42. 7 Mean, _40.2 



Similar differences in the freezing point of mercury have been noticed by other 

 observers; Parry, for instance, saw the mercury liquid at 43. The above mean 

 being so near to what is generally assumed ( 40) as the point of congelation, I 

 thought it best to apply no correction to the readings of the mercurial standard, 

 and to diminish that of the spirit standard, for temperatures lower than 40, by 

 the apparent difference, at that temperature, between the indications of the mer 

 curial and all other thermometers compared with it, or by the constant 1.5 ; thus 

 the maximum correction to the spirit standard becomes 6.0 at 60. 



Thus applying the proper corrections to the spirit standard S, according to ob 

 servations of February 4, 1854, spirit of naphtha became solid at 57, oil of sassa 

 fras at 46, bisulphuret of carbon at 26; oil of wintergreen clouded at 40, and 

 remained liquid at the maximum temperature of that day, viz : 63 ; the ethers 

 likewise remained unchanged. On the following day, aqua ammonia F. F. froze 

 solid from two hours exposure at a temperature of 52, chloric ether became solid, 

 and, after four hours of exposure, chloroform was covered with a granular follicle 

 at GG. 



