SPECIAL REPORT OF MR. HILL, ON MACHINERY. 417
engines, of which mention has already been made, with their cranks at right angles, the steam passing from the high-pressure cylinder into an intermediate receiver. To illustrate the extent to which this form of engine has come into vogue of late years for a class of steamers quite like those of our coasts and rivers, mention may be made of constructions of Escher, AVyss &Co., of Zurich. This firm, though situated far from any
Note. —The following table, prepared at the instance of the Engineering Department of the Navy, will show the results of practical experience on this question
Table exhibiting for comparison, the cost of the power, in pounds of steam per horsepower per hour, of a number of compound and non-compound tioo-cyUnder engines ; the quantities, as ascertained by indicator measurement, being corrected by adding, in the case of the non-compound engines, the known condensations in the cylinders, for their several measures of expansion as determined by the experiments of the Navy Department; and in the case of the compound engines, the quantity condensed in the steam-jackets, as estimated upon the basis of an experiment made with the pumping-engine of the Brooklyn ll r ater-Works in 1860.
DESCRIPTION OF ENGINE.
Pounds of steam consumed per hour per total horse-power.*
Pounds of steam condensed in the steam- jackets per total horse-power.t
Pounds of steam condensed per total horsc-power.J
Cost of the Power in Pounds of Steam per Horse-Power per Hour.
Pounds of steam con
sumed per total horse-power.§
Total.
Indicated.
«
The 60X36-in. Navy Engines,—
Of the U. S. S. Guerriere,
23.67
-
4.99
28.66
35.70
40.56
-
U. S. S. Delaware,
25.96
-
4.00
29.96
36.40
41.03
-
U. S. S. California,
24.50
-
5.10
29.60
35.40
41.00
-
U. S. S. Congress,
25.95
-
4.40
30.35
35.55
40.85
-
The 50X42-in. Navy Engines,—
Of the U. S. S. Alaska, .
23.40
-
4.10
27.70
35.30
41.40
-
tJ. S. S. Benecia,.
23.50
-
4.30
27.80
35.20
40.30
-
The 36X36-in. Navy Engines,—
Of the U. S. S. Resaca, .
23.80
-
5.00
28.80
34.80
43.00
—
U. S. S. Swatara,
23.00
-
4.20
27.20
33.70
38.60
-
The Compound Engines,—
Of the Steamer-, .
15.9
2.18
-
18.08
22.53
27.16
29.18
Steamer Italy,
16.7
2.18
-
18.88
21.49
26.10
31.57
Steamer Spain, .
16.6
2.16
-
18.76
21.85
26.54
32.77
Steamer City of Bristol,
16.2
2.11
18.31
21.01
25.85
28.07
Steamer Gracia, .
18.3
2.32
-
20.62
21.97
26.31
-
Steamer Patagonian, .
15.9
2.04
-
17.94
21.16
25.99
29.42
Steamer Batavia,
17.6
2.27
-
19.87
24.78
30.09
34.14
Steamer Egypt, .
17.7
2.28
-
19.98
24.89
29.42
32.00
Mean of the 60X 36-in. Engines, .
25.02
_
4.62
29.64
35.76
40.86
-
50X42-in. Engines, .
23.45
-
4.20
27.75
35.25
40.85
36X36-in. Engines, .
23.40
-
4.60
28.00
34.25
40.80
Mean of the Navy Engines, .
23.95
_
4.47
28.46
31.75
40.83
_
Compound Engines, .
16.86
2.19
19.05
22.46
27.18
31.02
* Inclusive of the quantity condensed in the production of the powers, t Calculated upon the basis of an experiment with the engine of the Brooklyn Water- Works.
t Due to all causes other than the production of the power.
§ Developed in the lower-pressure cylinder, inclusive of the quantity condensed in the steam-jackets.
53