Chapter XXVI

TUBULAR BOILER--SUPERHEATING STEAM--SURFACE CONDENSER.

Binner Downs engine, 1828--Fires around cylinder and
steam-pipes--Saving of coal--Surface condensation at sea--Superheating
tubes--Used steam returned to the boiler, 1828--Holland pumping
engine--Woolf at the Consolidated Mines--Laws of steam--Power
of heat from 1 lb. of coal--Loss of heat--Experiments at Binner
Downs--Surface condensation--Partial surface condensation for ships
or railways--Effect of superheating--Watt's theory doubted--Wheal
Towan and other engines--Loss of heat--Injection-water--Surface
condensation and superheating--Partial condensation engine--Duty
of chain pumping engine--Surface condensation by cold water or
air--Results of the experiment--Hayle Harbour--Condenser of copper
tubes, 1829--Suitability for steam-ships--Proposal to erect at his own
expense a marine engine with surface condenser and screw-propeller
for the instruction of the Admiralty, 1830.--Sketch of tubular boiler
and surface-air condenser--Screw draught--Preservation of heat in
condensing by air--Comptroller of the Navy--Patent of 1831--Boiler
within the condenser--Surface condensation by air or water--Safety
boiler of concentric tubes--Blowing vessel for air condensation
and draught--Tubes for distilling water--Steam pressure--Expansive
working--Robert Stephenson's statement--'Echo' steamboat,
1831--Bottle-neck boiler--Admiralty--Steam Users' Association--Mr.
Alexander Crichton's boiler and surface condenser--Captain Dick and
Captain Andrew--Captain King and the 'Echo' Page 315-362