iv CONTENTS OF VOLUME II. 



CHAPTER XIX. 



POLE STEAM-ENGINE. 



Return to Cornwall, 1810 Wheal Prosper pole vacuum engine, 1811 

 Cylindrical boilers, 1811 Steam pressure, 100 Ibs. Duty of engine, 40 

 millions Expansive working, 1811 Herland high-pressure pole puffer, 

 1815 Steam pressure, 150 Ibs. Boiler making Comparison with Watt's 

 engine Blue-fire Steam Patent specification Steam-ring stuffing box 



Engines in Lima A 33-inch pole-puffer more powerful than a 72-inch 

 Watt engine Description of pole engine and boilers Trevithick's cal- 

 culation Trial of Herland engines Steam-cushion Power of the pole- 

 engine Defective workmanship Sims examines the pole-engine 

 Opposition from shareholders Defective boilers Challenge to Woolf 

 Davies Giddy's opinion First cost, and cost of working one-third of the 

 Watt engine Meeting of opposing shareholders Duty of the high-pres- 

 sure steam pole puffer-engine, 1816 Comparison with the Watt engine 

 Combined high-pressure pole and cylinder for expansion Wheal Alfred 

 Watt engine converted to high pressure Wheal Chance combined engine 



Mr. Michael Williams's opinion Woolf- and Trevi thick Page 69-113 



CHAPTER XX. 



THE WATT AND THE TREVITHICK ENGINES AT DOLCOATH. 



Early steam-engines Semicircular boiler, 1775, net power 7 Ibs. on the 

 inch Watt's statement in 1777 Engines in Dolcoath Watt's engine, 

 1778 Watt's engine at Herland, 1798 Trevithick's tubular boiler, 

 1799 Reconstruction of the Carloose 45-inch, 1799 Gross and net 

 power of engines Comparison of Newcomen, Watt, and Trevithick en- 

 gines Boiler explosion, 1803 Strong rivalry with Watt Locomotive 

 at Coalbrookdale, 1803 Watt's proposed locomotive Competition in 

 Wales Numerous high-pressure engines, 1803 Patent difficulty 

 Watt's opposition, 1804 Government inquiry Competitive trials in 

 Wales Tramway locomotive, 1804 The bet Opposition because of 

 saving of labour Worcester engine West India Docks engine High- 

 pressure steam condensing engines One or two cylinders for expansion 

 Sirhowey boilers Mr. Homfray's opinion of the Watt opposition Mr. 

 Whitehead makes engines in Manchester Cylindrical tubular boiler in 

 Wales for large engines, 1805 Watt contests at Dolcoath, 1805 Steam- 

 blast Superiority of high-pressure whim-engines Proposed boiler for 

 the large pumping engine, 1806 Steam pressure The Watt boiler 

 Comparison of size of fire-place and coal used Dredger contract Theory 

 of steam Trevithick's Dolcoath boiler when applied to the Watt engine, 

 with expansive gear, to save 300^. monthly, 1806 Momentum of pumping 

 engine Continued tests of high and low pressure whim-engines at Dolcoath 

 Watt engine put aside, 1806 High-pressure engines ordered, 1806 

 High-pressure pumping engine for Wheal Abraham, 1806 Disputed patent 

 right Expansion reduces heat Boiler for the Watt 63-inch engine, 

 1806 Cost of Trevithick's boiler Advantage of small tubes in boilers 



