BETWEEN THE FREEZING AND BOILING-POINTS. 
261 
source of error common to the two. The limitation of the method of mixtures is, 
however, too well known to give the complete variation curve to any degree of accuracy. 
I have arranged in the following table the absolute values of the specific heat of 
water every 5 degrees between 0° and 100° from my measurements for a value of 
the Clark cell equal to I'43325 int. volts, and assuming the true ohm as correct, 
which gives the values in terms of the mechanical units in Reynolds and Moorby’s 
experiments. For comparison, I also include the measurements of Rowland and 
Miculescu, and those of Griffiths and of Schuster and Gannon, to the same value 
of the Clark cell. 
The minimum point of the specific heat, which Rowland found at 30°, really 
occurs at about 37°'5, but this was considered as likely by Rowland, for he says in 
his memoir (p. 199), “The point of minimum cannot be said to be known, though 
I have placed it provisionally between 30° and 35° C., but it may vary much from 
that.” And in another place (p. 200) he says, “ There may be an error of a small 
amount at that point (30 J ) in the direction of making the mechanical equivalent too 
great, and the specific heat may keep on decreasing to even 40°.” 
Absolute Value of the Thermal Capacity of Water in Joules per Calorie for 
Different Temperatures between the Freezing and Boiling-points, expressed in 
terms of a Clark Cell Value 1'43325 international volts at 15° C., and the Value 
of the true ohm 1'01358 B.A. Units. 
Temperature. 
s 
Barnes. 
Rowland. 
Miculescu. 
Griffiths. 
i 
Schuster 
and Gannon. 
° c. 
5 
4-2050 
4-206 
10 
4-1924 
4-196 
4-1857 
— 
— 
15 
4-1840 
4-188 
— 
4-1927 
— 
20 
4-1783 
4-181 
— 
4-1871 
4-1874 
25 
4-1746 
4-176 
— 
4-1816 
— 
30 
4-1725 
4-174 
— 
— 
— 
35 
4-1718 
4-175 
— 
— 
— 
40 
4-1718 
— 
— 
— 
— 
45 
4-1727 
— 
— 
— 
— 
50 
4-1743 
— 
— 
— 
■— 
55 
4-1764 
— 
-- 
— 
— 
60 
4-1790 
— 
— 
— 
■— 
65 
4-1815 
— 
— 
— 
-— 
70 
4-1843 
— 
— 
— 
— 
75 
4-1870 
— 
— 
— 
— 
80 
4-1899 
— 
— 
— 
85 
4-1927 
— 
— 
— 
— 
90 
4-1955 
— 
— 
— 
— 
95 
4-1983 
— 
— 
— 
— 
Mean . . . 
4-18326 
Reynolds and Moorby’s value . . . 
4-18320. 
