On the Expenditure of Heat in the Hot-air Engine. 355 
position that the surface of the working piston is 22100 square 
inches, the stroke six feet, and the number of revolutions, ten. 
Aggregate horse-power of air eviews with the gorreanontena expenditure of heat, and 
comparison with stea 
oe | H.P. |Heat expended. R. R. R" 
I 1 197 24869 1:260 | 1:960 |) .1:1:30 
“85 “85 279 2113 1:4°33 23°73 1: 216 
‘80 | -80 90 1989 1: 4°65 3-84 1: 2:32 
"7646 | -7646*| 292 1900 1:5°05 1: 4-00 1: 2-52 
“75 75 291 1864 1: 5°23 74°12 1:2-61 
‘70 | -70 1740 1:5°53 : 3-99 1:2°76 
4 3 273 1657 1:5-41 : 3-95 1:270 
*65 “65 268 1616 1:5°40 : 3:87 1:2-70 
“60 “60 24 14 1:5°31 3-63 1:2-65 
1 85 303 1:3:20 1:2-77 1: 1-60 
1 “80 333 3312 1: 3-29 1:2-72 1: 164 
1 75 360 3542 1: 3°34 1: 2-52 1: 1-67 
1 “70 384 3783 1:3:32 1: 2-50 1: 1-66 
1 3 398 3949 1:329 1: 2-49 1: 1:64 
1 65 403 4036 1:3:26 1:2:33 1:1-63 
1 -60 415 4302 1:3:25 1:2-23 1: 1°62 
"85 | :80 2309 ee ae Pim 1:2:18 
85 | % 2512 1:4:38 1: 3-45 1:2°19 
85 70 359 2727 1:4:31 1: 3:24 1: 215 
374 287 1:4°26 1:3:11 1:2:13 
85 65 381 2932 1:414 1: 2:99 1: 2-07 
85 397 1: 4:08 1:2°79 1: 2-04 
80 75 319 2183 1:473 1:3°75 1: 2°36 
80 | 70 340 2390 1:4:68 1: 3:52 1: 2:34 
80 t 356 2530 1:461 1:3:36 1: 2°30 
65 362 2606 1:4°59 1:327 1: 2-29 
“80 8 1:4:37 1:219 1:218 
5 -70 315 1: 5:00 1:3-77 1:2:50 
“75 z 331 2197 1;4:90 1:3:59 1:2-45 
“15 65 340 226 1:488 1:3:50 1:2-44 
“75 1: 4°67 1:3-20 1:2-33 
70 3 299 1870 1:5°23 1: 3:80 1:261 
65 306 1:5°17 1: 367 1: 258 
70 328 2144 1:5°01 1: 3-43 1: 250 
% | -75 9 1:5°67 1:461 1:283 | 
+} 70 > 1532 1:5°53 1:4°15 1: 2-76 
+ 65 281 1722 1: 5°32 1: 3:84 1:2-66 
3 1 922 1:5°14 1; 3:52 1: 2°57 
*65 60 287 1813 1:5°18 1:3:55 1: 2°59 
The column R” shows that there is still a ae theoretic bal- 
ance in favor of air, as respects economy of whe 
steam is worked with pretty large expansion. Moreover, the ad- 
int not be detected without 
aes not all _ the misp 
There paar a few errors in the text which somewhat anise the sss 
i ul undesirable, In i 
