FIG. PAGE 1. Opening Temple-Doors by Steam, B. C. 200 6 2. Steam Fountain, B. C. 200 7 3. Hero's Engine, B. C. 200 8 4. Porta's Apparatus, A. D. 1601 14 5. De Caus's Apparatus, A. D. 1605 15 6. Branca's Steam-Engine, A. D. 1629 17 7. Worcester's Steam-Fountain, A. D. 1650 21 8. Worcester's Engine, A. D. 1665 22 9. Wall of Raglan Castle 22 10. Huyghens's Engine, 1680 26 11. Savery's Model, 1698 34 12. Savery's Engine, 1698 35 13. Savery's Engine, A. D. 1702 37 14. Papin's Two-Way Cock 42 15. Engine Built by Desaguliers in 1718 43 16. Papin's Digester, 1680 48 17. Papin's Engine 50 18. Papin's Engine and Water-Wheel, A. D. 1707 53 19. Newcomen's Engine, A. D. 1705 59 20. Beighton's Valve-Gear, A. D. 1718 63 21. Smeaton's Newcomen Engine 65 22. Boiler of Newcomen Engine, 1763 67 23. Smeaton's Portable-Engine Boiler, 1765 73 24. The Newcomen Model 84 25. Watt's Experiment 89 26. Watt's Engine, 1774 98 27. Watt's Engine, 1781 104 28. Expansion of Steam 108 29. The Governor 115 30. Mercury Steam-Gauge and Glass Water-Gauge 117 31. Boulton & Watt's Double-Acting Engine, 1784 119 32. Valve-Gear of the Albion Mills Engine 121 33. Watt's Half-Trunk Engine, 1784 122 34. The Watt Hammer, 1784 123 35. James Watt's Workshop 129 36. Murdoch's Oscillating Engine, 1785 134 37. Hornblower's Compound Engine, 1781 136 38. Bull's Pumping-Engine, 1798 139 39. Cartwright's Engine, 1798 141 40. The First Railroad-Car, 1825 144 41. Leupold's Engine, 1720 148 42.