288 GLOSSAKT. 



Cam, tlie projectiug part of an eccentric or wavy wlic.il, to produce 

 alternate or reciprocating motion. 



Cant-hook, a wooden lever witli an iron hook near one end, used for 

 moving heavy articles, particularly saw-logs, etc. The end of the lever 

 is usually placed on the fulcrum, and the hook is fixed into the weight, 

 making it a lever of the second kind. 



Capillary attkaction, the attraction which causes liquids to rise in 

 very small tubes, or which retains water among sand and the particles 

 of soil. 



Centjie of gkavity, that point in a body or mass of matter, around 

 which all parts exactlj' balance each other. 



Centkifugal force, tending to fly from the centre, as the stone from 

 a sling. 



Centripetal force, drawing towards the centre, like the cord of a 

 sling. 



Chamfer, a slope, channel, or groove, cut in wood or metal. 



Chase, a wide groove. 



Chilled, applied to cast-iron rendered harder by casting the melted 

 metal against cold metal in the mould, for rendering certain jDarts harder 

 which are most liable to become worn. 



Chine, the ends of the staves of a barrel, outside the heads. 



Clamp, a cross-bar used to give additional strength, or to prevent 

 warping. Also, a piece of metal or wood, generally resembling in shape 

 the letter U, furnished with a screw, to fasten objects to a table or other 

 fixed bodies, or to each other. 



Cleat, a piece of wood nailed across, to give strength or security. 



Clevis, a draught iron, usually somewhat in the form of a bow or let- 

 ter U, placed on the forward end of a plow-beam for draught, or for 

 similar purposes. 



Click, a pawl, a latch, or the ratchet of a wheel. 



Cog, the tooth or projection of a cog-wheel. 



Collar, a metal ring around the cud of a cylinder of wood to prevent 

 splitting, or a ring around a piston or a journal, for securing tightness 

 or steadiness. 



Colter or Coulter, the upright cutting iron of a plow. 



Compass, an instrument for describing circles, measuring distances, etc. 



Counter-sink, a cavity made to receive the head of a screw. 



CouPLiNG-BOX, a contrivance for connecting shafts,' or throwing 

 wheels in and out of gear. 



Crab, a small portable crane. 



Cradle, a scythe with fingers, for cutting grain by hand. 



Crane, a machine for raising weights and tben swinging them side- 

 Avise ; generally made by attaching a pulley to a swinging bar or frame. 



Crank, an axle with a crooked portion for changing a rotary to an 

 alternate motion, or the reverse. A three-throw crank has three bends, 

 for driving three pumps, each stroke separated from the others by the 



