BY THE BOILING POINT OF WATER. 237 
simple law are given in the 6th column of the following Table. Column (7) gives 
the temperature from M. Reanavtt’s Table in the Annales de Chimie. 
Barometer corrected | Temp. 
age ‘ ReEe- 
SERIES. | and reduced to 32°. Boiling Linear J 5 4 
7 i Y. 
Taree. llineeane Difference.| NAULT’s |Difference LocaLiT 
Millim. |Eng. Inch|Observed* Hoxmula, 
527-5 | 20-79 |194:50 | 194-28 | + 0-22 |194:18 | +0:32 | Col Collon. 
528-05 194-25 | 194-33 | —0-08 | 194-24 | +0-01 | Aiguille du Moine. 
569-0 . 197-90 | 197-94 | —0-04 | 197-78 | +012 | Breven. 
575-9 . 198-43 | 198-51 | —0-08 |198-37 | +0-06 | St Bernard. 
588-1 : 199:45 |199-52 | —0-07 | 199-39 | +0-06 | Tacul. 
593-2 . 199-95 | 199-94 | 40-01 |199-80 | +0-15 | Do. 
606-9 . 200-93 |201-04 | —0-11 | 200-90 | —0-03 | Prarayon 
609°3 p 201-15 |201-:24 | —0-09 | 201-07 | +0-08 | Montanvert. 
610°15 : 201°35 |201:31 | +.0-04 | 201-15 | +0-20 
612.3 : 201-30 | 201-47 | —0-17 | 201-33 | —0-03 
638°6 , 203°55 |203-51 | + 0-04 | 203-36 | +0-19 
6750 : 204-60f| ... mae Ae ae Chamouni. 
723-6 : 209°47 | 209-54 | —0-07 |209-53 | —0-06 | Martigny. 
(2.) Daa ey reyes |" “(BY Mi Cree.) (9.) 
* Corrected for Index Error + 0°65. 
} Evidently a mistake; the error amounting to nearly 1}°. 
The following comparisons with the same apparatus and a different barometer, 
I find recorded as made at Edinburgh in January 1843. 
Barom. Boiling Point 
corrected. corrected. 
27-760 208-57 
29-040 210-72 
29-879 211-95 
30:064 212-18 
If we project the Alpine observations alone (which are the most consistent 
‘with one another), in the manner exemplified in my former paper, as is done in 
Plate IU, fig. 1, I find that they may be admirably represented by a straight in- 
_ terpolating line (giving the results recorded in column (5) of the preceding Table), 
and yield the following results. 
The uncorrected reading of the thermometer, at the standard pressure of 
30 inches, is 212°:75; at a pressure of 760 millimetres (29:922 inches), 212°-62, 
The Edinburgh observations (distinguished by the letter ¢), taken separately, 
give almost the same results. 
The Alpine observations above give a uniform rate of ascent of 543-2 feet for 
I’ of fall in the boiling point. This is when we use Lapiace’s barometric coeffi- 
