xxii LIST OF ILLUSTRATIONS ON WOOD. 



FIG. PAGK 



1. Plumb-line 17 



2. Masons', or perpendicular levels 18 



3. Delambre's perpendicular level for geodetic observations . . ... . 18 



4. Details of mechanism in the detent 20 



5. Mechanism of the regulating pendulum 24 



6. Anchor escapement 24 



7. Huygens's cycloidal pendulum , 25 



8. Foucault's pendulum experiment 27 



9. The lloman steelyard 29 



10. Weighing-machine, or Quintenz balance 30 



11. Peson 31 



12. Letter-weight 31 



13. Eoberval's balance 32 



14. Section of a hydraulic pump 34 



15. MM. Desgoffe and Ollivier's "sterhydraulic " press 36 



16. Hydrometer for liquids heavier than water 39 



17. Hydrometer for liquids lighter than water 39 



18. Gay-Lussac's centesimal alcoholometer 39 



19. Sykes's hydrometer 40 



20. Water-level . . . 42 



21. Spirit-level 42 



22. Horizontal of a plane obtained with a spirit-level 43 



23. Principle of fountains and artesian wells 44 



24. A fountain 45 



25. Geological section of the basin of the Seine between Paris and Langres. 45 



26 . Artesian well at Passy 46 



27. Pipette 48 



28. The Magic funnel 48 



29. The inexhaustible bottle 49 



30. Suction- pump 51 



31. Suction and force-pump 51 



32. Double- action pump (section) 52 



33. Another form (Owena's) of double-action pump (section) 52 



34. Common pump, with handle and lever 53 



35. Pump with crank and fly-wheel 54 



36. Bramah's oscillating pump 54 



37. The new water-wheels and pumps at Marly 55 



38. Plunger pump 56 



39. Stoltz's rotative pump . r ". . ... . 57 



40. Behrens's rotatory pump : phases of the rotatory movement .... 57 



41. Hand fire engine with lever .......... 59 



42. Section of the horizontal steam fire-engine, showing the arrangement of 



the force-pumps -> -. . 62 



43. Piston of M. Deleuil's air-pump 64 



44. Pneumatic tube of the atmospheric railway of Saint-Germain .... 67 



45. Air-gun ; full view and section 70 



46. Hydraulic ram for compressing air. Theoretical diagram 72 



47. Double-action compression pump, Fryer's system (New York) ... 72 



