APPENDIX 187 



diameter of driver by its speed and divide the product 

 by the required speed of driven pulley. 



Example : Diameter of engine pulley, 20 inches ; speed 

 of engine, 200 revolutions per minute; speed of driven 

 pulley, 200 revolutions per minute. 



20 X 200 -=- 200 = 20 = diameter of driven pulley. 



CARE AND MANAGEMENT OE ENGINE. 



I. It is essential to have all parts of the engine well 

 oiled, using nothing but the best oil. 



2^ Keep the engine clean. The shiny parts should be 

 brightened at least once a day. 



3. Keep the engine well "keyed up." At both ends 

 of the connecting rod are keys, the purpose of which is to 

 keep the brass boxes tight enough to prevent undue play. 

 The "keying" consists in loosening the burrs next to the 

 key and then tapping the latter lightly until the unneces- 

 sary play is taken up. Care must be taken, however, not 

 to get the brasses too tight or a hot box will be the result. 

 "Pounding" is usually caused by not having the keys 

 properly set. It is also caused by wet steam and water in 

 the cylinder. 



4. Keep stufifing boxes carefully packed to prevent 

 leakage of steam. The packing should be treated with 

 graphite or good cylinder oil and packed firmly around 

 the rod, but it must not be too tight, otherwise power 

 is lost in friction. If the rod has become scored or rusty, 

 smooth it with emery cloth before packing. 



5. The packing rings in the piston should be kept in 

 good repair. The clicking noise sometimes heard in 

 cylinders is due either to the packing ring wiping over 



