grossing cotton, blowing furnaces,
    driving piles, and dredging earth out of rivers. 
Pressing cotton, power necessary for. 
Priming, nature and causes of. 
Priming, if excessive, may occasion explosion. 
Propeller, screw, description of. 
Proportions of screws with, two, four, and six blades. 
Proving of boilers. 
Prussiate of potash for case hardening. 
Pumping engines, mode of erecting,
  mode of starting. 
Pumps, loss of effect in, at high speed and with hot water,
  causes of this loss;
  remedy for. 
Pumps used for mines. 
Pump, air, description, of,
  action of. 
Pumps, air, proper proportions of,
  single and double acting. 
Pump, centrifugal, better than common pump. 
Pump, cold water, description of. 
Pump, feed, description of,
  action of;
  proper dimensions of;
  rule for proportioning;
  plunger of;
  valves of;
  independent. 
Pump valves for mines, &c. 
Punching and shearing boiler plates.

Railway wheels, bursting velocity of. 
Railway trains, resistance of. 
Rarefaction or exhaustion produced by chimneys. 
“Rattler” and “Alecto,” trials of. 
Registration, benefits of. 
Regnault, experiments on heat by. 
Regulator, a valve for regulating the admission of steam in locomotives,
  description of;
  various forms of. 
Regulator, Clark’s, patent steam and fire. 
Rennie, experiments on friction by. 
Resistance, experienced by railway trains. 
Resistance of vessels in water,
  mainly made up of friction;
  experiments on. 
Resistance and speed of vessels influenced by their size. 
“Retribution,” boilers of, by Messrs. Mandslay. 
Riveting and caulking of land boilers. 
Rocking motion of locomotives. 
Rolling circle of paddle wheels. 
Rotatory engines, definition of. 
Rotative engines, definition of. 
Rust joints, how to make.

Safety valve, area of, in low pressure engines,
  in locomotives. 
Salinometer, or salt gauge, how to use,
  how to construct. 
Salt, accumulation of, prevented in marine boilers by blowing off, if allowed to accumulate in boilers may occasion explosion;
  amount of, in sea water. 
Salt water produces surcharged steam. 
Salting of boilers, what to do if this takes place. 
Sawing timber, power necessary for. 
Scale in marine boilers. See also Salt. 
Scale preventer, Lamb’s. 
Scrap iron, unsuitable for case hardening. 
Scraping tools for metal surfaces. 
Screw. 
Screw engine, geared oscillating, description of,
  direct acting, description of. 
Screw engine, direct acting, by Messrs. John Bourne & Co. 
Screw engines, best forms of. 
Screw frame in deadwood. 
Screw propeller, description of. 
Screw propeller, mode of fixing on shaft,
  modes of receiving thrust;
  apparatus for lifting;
  configuration of;