18 
BULLETIN 718, U. S. DEPARTMENT OF AGRICULTURE. 
used in mountain mills. The fittings and fixtures comprise grates, 
water column attached with gauge cocks, water gauge, steam gauge, 
safety valve, check valve, stop cock, whistle, blow-off valve, stack and 
guy rods (four times the length of the stack) ; injector and spark 
arrester extra. 
The usual specifications for a 
>0 horsepower boiler are- 
25 horse- 
power. 
30 horse- 
power. 
36 
52 
38 
30 
34 
96 
X 
1 
20 by 24 
16 
25 
16- 
5,300 
6,300 
36 
do 
52 
Height of fire box 
.:. do.... 
40 
Width of fire box 
do 
30 
Number of 3- inch tubes 
34 
Length of tubes 
inches.. 
120 
do 
i 
Thickness of furnace plates 
Thickness of tube sheets and hea-bs 
Ske otd^rne . 
do.... 
do.... 
...do.... 
f 
20 bv 24 
do.... 
16 
feet.. 
25 
16 
Weight of bare boiler, on skids. . . 
Weight, with fixtures attached 
pounds.. 
do.... 
5, 800 
6,900 
The following is a list of the component parts of a 25 and 35 
horsepower center-crank horizontal engine and the approximate cost 
of replacing each part : 
Size of cylinder inches 
Bed frame 
Connecting rod, complete 
Crank shaft, complete 
Crank pin, brass ' 
Crosshead-pin, brass ." 
Crosshead, complete 
Cylinder head, plain 
Cylinder h?ad , with gland 
Cylinder, complete 
Eccentric rod 
Eccentric rod head 
Eccentric and strap 
Flywheel 
Governor pulley ' 
Piston ring, each , 
Piston ring with rod fitted 
Piston-rod gland 
Pulley : -. 
Steam-chest cover 
Valve 
Valve stem 
Valve-stem gland 
Valve-stem bar 
25 horse- 
power. 
10 by 12 
$114.00 
58.20 
96.00 
13.00 
7.50 
26.52 
13.20 
19.80 
69.60 
5.40 
7.68 
12.00 
46.80 
6.12 
2.40 
15.72 
3.48 
13.90 
8.34 
3.72 
6.54 
4.86 
7.26 
35 horse- 
power. 
10 by 13 
$114. CO 
64.40 
116.00 
14.00 
7.50 
26.52 
15.60 
24.00 
78.00 
6.12 
7.68 
13.68 
46.80 
6.eo 
2.70 
18.24 
3.48 
13.90 
8.34 
^3.84 
6.72 
4.86 
7.2n 
CAEE OF BOILER. 
The first duty of an engineer when he enters his boiler room in 
the morning is to ascertain how many gauges of water there are in 
the boiler. Never unbank or replenish the fires until this is done. 
If the water is low, cover the fires with ashes or fresh coal and close 
the drafts and ash-pit doors, Do not turn on the feed or tamper 
