18 BULLETIN 118, U. S. DEPAETMENT OF AGEICULTUKE. 



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 25 or 30 horsepower boiler are 



Diameter of boiler inches 



Length of fire box '_' ^^ 



Height of firebox [..... do 



Width of fire box ^jq 



Numlier of 3-inch tubes 



Length of tubes. ■."..".'.■."." '.".".■ .'."." .'.ta'ches!; 



Thiclcness of stiell. rig 



Thickness of furnace plates ■. do 



Thickness of tube sheets andhea'is d'l 



Size of dome ] do 



Diameter of stack ....'.'.'.'.'.'.'.do..'.'.' 



Length of stflck '.'. ' feet" 



Number of steel in stack 



Weight of bare boiler, on skids ."'."" pounds 



Weight, with fixtures attached " ' do " 



25 horse- 

 po\Ycr. 



20 by 24 



16 



25 



16- 



5, 300 



6,300 



30 horse- 

 power. 



36 

 r2 

 40 

 30 

 34 

 120 



20 bv 24 



16 



25 



16 



5, SOO 



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 



Bcdfrariie 



Connecting rod, complete 



Crank shaft, complete ' ' ] ^ ^ 



Crank pin, brass 



Crosshead-pin, brass 



Crosshoad, complete 



Cylinder head, plain 



Cylinder head , 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-stcm gland 



Valve-stem Ijar 



25 horse- 



35 horse- 



power. 



power. 



10 by 12 



10 by 13 



$114.00 



$114.(0 



58.20 



64.^0 



96.00 



116. 00 



13.00 



14.00 



7.50 



7. .50 



26.52 



26.52 



13.20 



15. 60 



19.80 



24.00 



69.60 



78.00 



5.40 



6.12 



7.68 



7.68 



12.00 



13.68 



46. SO 



46. SO 



6.12 



6. CO 



2.40 



2.70 



15.72 



18. 24 



3.48 



3.4S 



13.90 



13.90 



8.34 



8.34 



3.72 



3.84 



6.54 



6.72 



4.86 



4.S6 



7.26 



7.2;i 



CARE OF BOILER. 



The first duty of an engineer when he enters his boiler room in 

 the morning is to ascertain how many gauges of Avater 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 clo.se 

 the drafts and ash-pit doors. Do not turn on the feed or tamper 



