(pill 



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CONTENTS. 



THE STEAM ENGINE. 



PAQK 



CHAP. I. 1. The steam engine. 2. Consists of two essential parts. 

 3. The boiler. 4. Material employed in its formation. 5. 

 Feeding apparatus. 6. Importance of keeping the water in the 

 boiler at a proper level. 7. Wet and dry steam. 8. Priming. 

 9. Means of ascertaining the level of the water in the boiler. 10. 

 Self-acting feeders. 11. Safety valve. 12. Steam gauge. 13. 

 The furnace. 14. Proper mode of feeding the furnace. 15. 

 Rarely observed. 16. Contrivance for supplying fuel . . 1 



CHAP. II. 17. Method of regulating the activity of the furnace. 

 18. How steam is made to produce a mechanical effect. 19. The 

 cylinder and piston. 20. Metallic pistons. 21. Estimate of the 

 force with which the piston is moved. 22. Transmission of this 

 force. 23. Piston rod. 24. Cocks, valves, and slides. 25. 

 How employed. 26. Stroke of the engine. 27. Effective pres- 

 sure. 28. Supply of steam to the cylinder. 29. By valves. 

 30. By slides. 31. Seaward's slides. 32. Single cock. 33. 

 Four-way cock. 34. Low and high pressure, more properly 

 called condensing and non-condensing, engines. 35. Objections 

 to the latter and countervailing advantages. 36. Condensing 

 engines. 37. Condensing apparatus. 38. Air-pump. 39. Cold 

 water pump. 40. Hot water pump . . . . .17 



CHAP. III. 41. Comparative merits of the two kinds of engines. 

 42. Various modes of transmitting force. 43. Description of a 

 factory engine. 44. The governor. 45. The eccentric. 46. The 

 fly-wheel. 47. Parallel motion. 48. Barometer gauge. 49. 

 How to compute the effective moving force of the piston. 50. 

 Method not considered sufficiently accurate. 51. Indicator. 

 52. Mode of recording its positions. 53. Its application in 

 finding effective force. 54. Watt's counter. 55. Conclusion . 33 



THE EYE. 



CHAP. I. 1. Pleasures and advantages of the power of vision. 2. 

 Reasons why a knowledge of the structure and functions of the 

 eye is desirable. 3. Description of the eye. 4. Sclerotica and 



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