208 
ME. W. rAIRBAIEX AXD ^FR. T. TATE OX THE DEXSITT 
Table of Eesults, deduced fi'6m the preceding determinations of the maximum tempe- 
rature of saturation and specific volume of steam, at pressm-es of from 15 to 70 lbs. 
per square inch. 
Number 
of 
Exper. 
Maximum temperature 
of saturation, 
Fahrenheit. 
Pressure of steam, 
in inches of mercury. 
Specific volume of 
tlie steam. 
Maximum tempera- 
tare of saturation. 
Centigrade. 
Pressure of steam, 
in millimetres 
of mercury. 
1. 
242-89 1 
242-92 J 
0 
■ 242-90 
53 60 ] 
53-63 
53-61 
943-12 
0 
117-16 
1361-7 
2. 
244-90 1 
244-74 J 
244-82 
55-60 ] 
55-44 
55-52 
908-03 
118-23 
1410-1 
O 
245-42] 
245-02 J 
■ 245-22 
56-08’ 
55-70 
55-89 
892-54 
118-45 
1419-6 
4. 
255-37 
255-62 
^ 255-50 
66-70 
66-97 J 
• 66-84 
759-44 
124-16 
1697-7 
5. 
263-20 1 
263-09 
> 263-14 
76-26 
76-13 J 
. 76-20 
649-24 
128-41 
1935-4 
6. 
267-35] 
267-08 J 
. 267-21 
81-71] 
81-36 
. 81-53 
635-30 
130-67 
2070-8 
7. 
269-24] 
269-16 J 
. 269-20 
84-36 
84-25 
. 84-20 
605-65 
131-77 
2138-9 
8. 
274-76 
92-23 
584-44 
134-86 
2342-6 
9. 
273-30 
90-08 
543-17 
134-05 
2287-9 ( 
10. 
279-42 
99-60 
514-98 
137-45 
2529-8 
11. 
282-55] 
282-61 
. 282-58 
104-48 
104-60 
. 104-54 
497-25 
139-21 
2655-2 
12. 
13. 
287-49 1 
287-00 
292-53 
. 287-25 
112-82 
112-75 
122-25 
, 112-78 
458-30 
433-12 
141-80 
144-74 
2864-6 
3105-1 
14. 
288-25 
114-25 
449-62 
142-36 
2901-9 
Section II . — Experiments at Pressures less than that of the Atmosphere. 
As there would be a difficulty in maintaining the copper steam-bath perfectly air- 
tight when the elasticity of the steam is considerably less than that of the atmosphere, 
the construction of the ^.pparatus was modified in the following manner : — 
The extremity of the stem of the glass globe, passing through the outer tube, had its 
extremity inserted in a deep mercury-bath, the surface of which was exposed to the 
pressure of the atmosphere. The elevation of the column of mercury in the globe-stem 
above the level of the mercury in the bath being taken at difterent temperatures, and 
the corresponding elevation of the mercury in the barometer being observed, the differ- 
ence of these two columns at once gives the elasticity of the vapour in the globe for the 
corresponding temperature. The maximum temperature of saturation, in this case, 
takes place at that point Avhere the column of mercury, measuring the elasticity of the 
vapour in the globe, begins to deviate from the column of pressure measuring the elasti- 
city of saturated steam. 
Plate VIII. fig. I is a section of the copper boiler and apparatus arranged for the low- 
pressure experiments, B is the copper boiler, Avith its cover removed and supported on 
the strong tripod as before ; o o the outer glass tube I^ inch diameter and 32 inches 
long, fixed as before in the stuffing-box s, but in these experiments open at the bottom, 
