THE PROPERTIES OF WATER AND OF STEAM. 
119 
Fairbairn and Tate. Superheated Steam. ‘Edinb. Trans.,’ vol. 23, 18G2, p. 147. 
Results arranged in isotherms, and Pressures and Y.D.’s corrected for vapour 
pressure of mercury, using (1) Pressures used by Rankine, (2) Pressures by 
Ramsay and Young. 
Tempera¬ 
ture. 
Tempera¬ 
ture. 
Weight. 
Volume. 
Pi- 
P 3 . 
V. D. (1.) 
V. D. (2.) 
0 F. 
°C. 
grms. 
c.cs. 
millims. 
millims. 
302-88 
150-5 
0-01845 
197-3 
132 3 
134-0 
9-31 
9-19 
0-02625 
197-3 
184-6 
186-3 
9-48 
9-39 
0-03530 
197-3 
250-4 
252-1 
9-41 
9-34 
003435 
197-3 
242-0 
243-7 
9-46 
9-40 
0-05670 
197-3 
408-6 
410-3 
9-25 
9-22 
251-64 
122-0 
0-01845 
197-2 
123-8 
124-7 
9-29 
9-22 
0-02625 
197-2 
171-5 
172-4 
9-53 
9 48 
0-03530 
197-2 
234-0 
234-9 
9-39 
9-36 
0-03435 
197-2 
226-1 
227-0 
9'46 
9-42 
11 
0-05670 
197-2 
381-6 
382-5 
9-25 
9-23 
200-74 
93-75 
0-01845 
1971 
114-7 
115-1 
9-31 
9-28 
0-02625 
197-1 
159-9 
160-3 
9-49 
9-47 
0-03530 
197-1 
217-1 
217-5 
9-41 
9-39 
0-03435 
197-1 
210-0 
210-4 
9-46 
9-44 
0-05670 
197-1 
353-2 
353-6 
9-28 
9-27 
180-72 
82-6 
0-04670 
197-0 
340-2 
340-5 
9-35 
9-34 
165-45 
74-15 
0-03435 
197-0 
197-3 
197-5 
9-53 
9-52 
0-05670 
197-0 
259-3 
259-5 
11-98 
11-97 
150-18 
65"65 
0-01845 
196-9 
105-7 
105-9 
9-34 
9-32 
55 
0-02625 
196-9 
147-6 
147-8 
9-50 
9-49 
55 
003530 
196-9 
176-1 
176-3 
10-72 
10-71 
55 
0-03435 
196-9 
177-1 
177-3 
10-37 
10-35 
100-0 
37-75 
0-01845 
196-8 
44-6 
44-7 
20-3 
20-3 
Hirn, in his ‘ Theorie Mecanique de la Chaleur,’ vol. 1, 3rd Ed., p. 468, gives a 
table of the densities of saturated vapour at various temperatures, ranging from 98° 
to 196°. As these agree absolutely with the results calculated from Regnault’s 
measurements, and as neither the method adopted by Hirn, nor his individual obser¬ 
vations would appear to lead one to anticipate such concordance, we would suggest 
that it may be attributed to the “ trace de sentiment” with which he credits the 
assistant who interpreted his results. 
In conclusion, it may be noted that Regnault made experiments on the densities 
of saturated steam at low temperatures for hygrometric purposes, and has shown that 
it is practically normal at temperatures between 0° and 27° (‘ Annales de Chimie ’ [3], 
vol. 15, 1845, p. 129, et seq.). 
Note. —In Plate 7 the curves representing the relations of temperature, pressure, and volume of 
unsaturated and saturated steam are given on a scale large enough, we hope, to prove of practical use. 
For this purpose they have been divided into three sets, a different scale, however, being applied to each 
set. The pressures are given in metres of mercury; the volumes, in cubic centimetres per gramme. 
The heavy line shows the volumes of saturated vapour, and may be termed the orthobaric line. 
