THE STEAM-ENGINE THIRD LECTURE 451 



Methods of Connecting the Piston- Rod and Beam in the Double- Acting Engine. Rack and Sector. 

 Parallel Motion. Connexion of Piston-Rod and Beam. Connecting Rod and Crank. Fly- 

 Wheel. Throttle-Valve. Governor. Construction and Operation of the Double-Acting Engine. 

 Eccentric. Cocks and Valves. Single-Clack Valves. Double-Clack Valves. Conical Valves. 

 Slide Valves. Murray's Slides. The D Valves. Seaward's^Slides. Single Cock. Two-way 

 Cock. Four-way Cock. Pistons. Common hemp-packed Piston. Woolf's Piston. Metallic 

 Pistons. Cartwright's Engine. Cartwright's Piston. Barton's Piston. 



THE STEAM-ENGINE FOURTH LECTURE 491 



Analysis of Coal. Process of Combustion. Heat evolved in it. Form and Structure of Boiler. 

 Wagon-Boiler. Furnace. Method of Feeding it. Combustion of Gas in Flues. Williams's 

 Patent for Method of Consuming unburned Gases. Construction of Grate and Ash-Pit. Magni- 

 tude of Heating Surface of Boiler. Steam-Space and Water-Space in Boiler. Position of Flues. 

 Method of Feeding Boiler. Method of Indicating the Level of Water in the Boiler. Lever, 

 Gauges. Self- Regulating Feeders. Steam-Gauge. Barometer- Gauge. Watt's Invention of the 

 Indicator. Counter. Safety -Valve. Fusible Plugs. Self-Regulating Damper. Brunton's Self- 

 Regulating Furnace. Gross and Useful Effect of an Engine. Power and Duty of Engines. 

 Horse-Power of Steam-Engines. Table exhibiting the Mechanical Power of Water converted 

 into Steam at various Pressures. Evaporation proportional to Horse-Power. Sources of Loss of 

 Power. Absence of good Practical Rules for Power. Common Rules followed by Engine-Makers. 

 Duty distinguished from Power. Duty of Boilers. Proportion of Stroke to Diameter of .Cylin- 

 der. Duty of Engines. Cornish System of Inspection. Table showing the Improvement of Cor- 

 nish Engines. Beneficial Effects of Cornish Inspection. Successive Improvements on which the 

 increased Duty of Engines depends, traced by John Taylor in his " Records of Mining." 



THE STEAM-ENGINE FIFTH LECTURE 525 



Railways. Effects of Railway Transport. History of the Locomotive Engine. Construction of 

 Locomotive Engine by Blinkinsop. Messrs. Chapman's Contrivance. Walking Engine. Mr. 

 Stephenson's Engines at Killingworth. Liverpool and Manchester Railway. Experimental Trial 

 of the "Rocket," " Sanspareil," and "Novelty." Method of Subdividing the Flue into Tubes. 

 Progressive Improvement of Locomotive Engines. Adoption of Brass Tubes. Detailed Descrip- 

 tion of the most Improved Locomotive Engines. Power of Locomotive Engines. Position of the 

 Eccentrics. Pressure of Steam in the Boiler. Dr. Lardner's Experiments in 1838. Resistance 

 to Railway Trains. Dr. Lardner's Experiments on the Great-Western Railway. Experiments 

 on Resistance. Restrictions on Gradients. Compensating Effect of Gradients. Experiment 

 with the ' Hecla." Disposition of Gradients should be Uniform. Methods of surmounting Steep 

 Inclinations. 



