TRANSACTIONS OF SECTION A, 631 
Winkelmann’s formula. It may also be worth remarking that a direct experi- 
ment of Rowland’s gave the ratio s19.°/s?3 = 1:0024, for which the ahove formula 
would give the value 1:0033. 
TABLE OF SPECIFIC HEAT OF WATER. 
) 
| h Rowland 
#°C | Joules 8, st | (CB) (reduced) 
Range 0° to 60°. Callendar and Barnes. 
Formula, s; = 0°9982 + 0:0000045 (¢ —40)?. 
0° 4-203 10054 2a ae) HOR) at 
5° 4/196 1:0037 10045 | 5-023 5-023 
10° 4-190 1-0022 10037. | 10-037 10-044 
15° 4°185 1:0010 10030. |. 15-045 15-054 
20° 4-181 1:0000 10024 | 20038 | 20-057 
25° 4:178 0.9992 10018 | 25-045 25:053 
30° 4-176 0:9987 1:0013 | 30-039 30-043 
35° 4-174 0:9983 10009 35-032 35-039 
40° 4-174 09982 1:0006 | 40:024 Peabody 
45° | 4174 0:9983 10003 | 45-016 45-000 
50° 4176 0:9987 10001 | 50-008 50-040 
55° 4178 0-9992 1:0000 53-002 55-080 
60° 4-181 1:0000 1:0000 | 60-000 60-120 
Range 60° to 220°C. Regnault (corrected). 
Formula, s, = 0'9944 + 0:00004 ¢ + 0:0000009 @?. 
| ! 
60° 4181 | 1:0000 /  4:0000 | 60-000 60°12 
65° 4184 | 1:0008 1:0000 65:002 | 65:16 
70° 4-188 1:0016 10001 70008 70:20 
(ie 4191 1:0024 1:0002 75018 75°24 
80° 4195 1:00383 1-0004 80°032 80°28 
85° 4-199 1:0043 1:0006 85051 85°32 
90° 4:203 1:0053 1:0008 90°075 90°36 
95° 4-207 1:0063 10011 95°105 95:40 
100° 4-212 10074 10014 1007138 100744 
| Shaw 
110° 4:222 1:0097 1:0020 110°22 110°67 
120° 4-232 1:0121 1:0028 120°33 120°73 
130° 4°243 10148 1:0036 130°47 130°80 
140° 4255 J:0176 1:0045 140°63 140°88 
150° 4:267 1:0206 1:0055 150°82 15101 
160° 4-281 1:0238 1:0066 161°05 161°20 
170° 4:295 1:0272 1:0077 171-31 171°61 
180° 4310 1:0308 1:0089 1381°60 182714 
190° 4326 1:0345 1:0102 191-94 oe 
200° 4-342 1:0384 10115 202°31 = 
210° 4°359 10425 ee wheOLSO 212°72 — 
220° 4:377 1:0467 1:0145 223°18 — 
It would appear, however, from the authors’ preliminary observations at higher 
points, that the curve of variation of specific heat is not quite symmetrical, but 
somewhat flatter between 60° and 100°. ‘he rate of change of the specific 
heat at 100° as given by the formula (CB), if extrapolated, is more than twice as 
great as that given by Regnault, and at 200° about four times as great. The 
experiments of Regnault apply particularly to this portion of the range, for which 
they remain the standard, and have been universally adopted. Until more 
accurate experiments are forthcoming, it would be extremely desirable to retain 
