324 J. H. Alexander on the Tension of igi of Water 7 ( 
Error of ae eo | 
Pig ‘Maximum. | Minium 
From experiments of Academy of Sci aa ‘ —00-64 F. —0°-08 
Mr. Regnault, +0 -92 +0: 
‘Mean error by both, . . 2. - se «| 0% Hie 
The nearness of these limits and the Suialitieee of the nu umber 
enclosed by them warrant, I think, a sole and entire reliance 
upon the formula, in the present state of experimental knowled ge 
on the subject. I do not introduce into combination any of the 
other and earlier series of observations; because, from the way in 
which they have been reported by their respective authors, they 
do not admit the application of the same methods of co comparison ; a 
and because it may justly be supposed that the apparatus, intel 
lectual and mechanical, resorted to in 1829 and since, is para- 
: oe es accuracy to what had been at disposal i in precediie a Te- 
i 
a shall only, therefore, i in farther illustration of the present orm- 
ula 
proposed by other mathematicians ; only extending, in, point oe 
fact, for this purpose, a similar comparison which MM. Dulong” 
- and. Arago have already instituted; and using, except for the 
" last c olumn, quantities from the calculation of these philosophers. 
ae table is founded upon the same eleven observations of them 
wn, just now quoted ; and they have given for each instance 
the individial deviations of the ‘several formule from the tes sult 
experiment. Not to employ so much room, have thought it. 
equally satisfactory to give the general restilts and inferences, as 
under. The deviations are given in Centigrade degrees, and be- 
long 1 to the same side of the equation with the Oar ee given) 
pective formule. - , gee 
# Say 
a 
F 1 ed Dy ae 
; | tredgola. Roc or a THA 
aximum ee in excess, . .| 0°69 | 0%53)| 0°80 |™0°-405| “9? Tao} 
- |Maximom defect, .. | 2:11] 0575} .0 -25| 0 os 1-20 
: Nn ge Bea: withont regard to signs, 0 | 0 37 0 “M4 
do. 1+ 
: The three first are given’ by Mr. Dulong, Wher a : copious enue 
meration of different ermal as agreeing the best with, om 
isa Peete of the temperature ; but Mr. Coriolis ses, instea 
of an integral, a mixed fractional index. His exponent, instea 
of 7 as Dr. Young took, or 6 as Creighton and Tredgold prefer- 
, or 5:13 as Southern chose, or 5 as Dulong adopted, is 5° 335, ie 
; coincidence with the natural law is oaly empirical ang can 
