10 Mr. J. Herapath on the irregular 



two or three times, by which I thought I should produce the 

 same effect on the thermometer as if I had allowed it to reach 

 its maximum in water of about 10.5° or 106°. Cooling down 

 the bulb considerably, I observed the mercury to be 51°'47, 

 exceeding apparently its former temperature by 0, 2. 



Exp. 8. Being apprehensive that I might have raised the 

 temperature of the mercury a little, by the excess of the tem- 

 perature in the bulb at the time of the re-immersion, I re- 

 peated the experiment at the distance of 1 2 or 24- hours in 

 precisely the same way, except that I brought the bulb, pre- 

 vious to taking the second temperature, to as near as I could 

 this mercurial temperature, by putting it in water and then 

 quickly wiping it dry with a handkerchief. The air being 

 50° near the wall, the numbers were 48°'53 and 48°'67. 



Exp. 9. Twenty-four hours afterwards the same apparatus 

 and precautions gave 45°'93 and 46°' 10, the air being 46 0, 7. 



Exp. 10. At the end of 12 or 24 hours more, in an atmo- 

 sphere of 47°, I obtained 4G°'2 and 46°'4. 



Exp. 1 2. Being desirous of trying the experiment so as to 

 ascertain whether immediate repetitions with mercury would 

 be attended with successive augmentations of temperature, I 

 put my glass containing the mercury in the same room with 

 my thermometer. About four hours afterwards, the air near 

 one of the walls being 48°'5, I repeated the experiment with 

 all the preceding precautions, to which I added that of cool- 

 ing the thermometer's bulb, previous to the last immersion, a 

 degree lower at least than the mercury. The numbers were 

 48°'5 and 48° - 73. A few minutes afterwards I raised the 

 thermometer again to 105°; and, with the same care in cool- 

 ing the bulb a degree or more beneath the mercury, took the 

 mercury at 48 0, 83. Another repetition with like precautions 

 gave 48 0, 9, and another 48 0, 97. These experiments alto- 

 gether occupied about 20 minutes. 



Half an hour after I had finished I observed the same 

 thermometer near the wall stand at 48°'8 ; the mercury indi- 

 cating by this instrument a temperature of48°'87. 



Exp. 13. Twenty-four hours afterwards, the air being 

 48°'47, I repeated the experiment with the same care and 

 precautions. The numbers were at 



8 h 40' A.M. before heating thermom. 47°'47 



8 43 . . . after ditto 47 '77 



8 47 * ' • after 2d ditto 47 -93 



8 50 3d ditto ..... 48 '07 



8 55 4th ditto 48 '20 



9 5th ditto 48-40 



9 5 6th ditto 48 '60 



9 10 7th ditto 48 '77 



the 



