COMPRESSED AIR 249 



until now they are made almost as diminutive as a watch- 

 maker's hammer. Steam engines of most api)roved t3T3es, 

 common water wheels, Pelton wheels, or the more modern tur- 

 bines furnish the power for compressing the air. Air com- 

 pressors or pumps are constructed to be driven from belting, 

 with gears or combined direct with a reciprocating steam 

 engine. The initial power being settled upon, it only re- 

 mains to lay the mains about the plant, provided at con- 

 venient distances with valves, to which, by means of rubber 

 hose, the individual tools may be connected. 



This gives a flexibility to the plant hitherto unknown, 

 for the mains once laid and convenient openings provided 

 any desired tool may be brought to bear at any part of the 

 shop, yard, building, bridge or roadbed. Think of the vari- 

 ety of work done in a shipyard, most of which was until 

 recently done by hand. There are so many operations going 

 on simultaneously that it is difficult to find a starting point. 

 Pneumatic pmiches of all sizes are now portable, adapted to 

 be hung from cranes or bars or supported in any way at any 

 angle, and may be used either in the shed, in the open, out- 

 side or inside the ship's hull, wherever, in fact, the pon- 

 derous plates may be or the holes needed. Similarly, pneu- 

 matic riveters are portable, and, with a velocity scarcely 

 conceivable, they either press in a glowing rivet by sheer 

 force or through a series of rapid percussions set it much 

 better than by hand and quicker than the old fashioned 

 hydraulic press used tools. Visit the boiler shop and view 

 with amazement how easily the pneumatic tools clip off 

 the huge rivet heads, upset stay bolts, calk seams, chip 

 out a manhole or cut a strip from the edge of a nine foot 

 plate m one piece without breaking it, as easily as the ordi- 

 nary planer would do without all the necessary adjustment. 

 Witness, if you please, the cutting of the hundreds of side 

 lights in the ship's side with pneumatic tools and then if 

 possible find a yard which still adheres to the hand ratchet 

 drill and "old man" chipping out with the chisel and ham- 

 mer so common only a year or so ago, if you wish to realize 

 how compressed air and the tools which it actuates have 

 revolutionized this one industry. For smaller work than 



