LIST OF ILLUSTRATIONS. 



PAGE 



1. Refraction of Parallel Rays by Plano-convex Lens, . . .67 



2. Ditto by Double-convex Lens, . . 67 



3. Refraction of Converging Rays, . . . . .68 



4. Refraction of Diverging Rays, ..... 68 



5. Formation of Images by Convex Lenses, . . . .70 



6. Spherical Aberration, ...... 70 



7. Chromatic Aberration, . . . . . . .72 



8. Section of the Achromatic Object-glass, .... 75 



9. Effect of Covering-glass, ...... 76 



10. Action of Simple Microscope. ..... 78 



11. Simplest" form of Compound Microscope, . . . .82 



12. Complete Compound Microscope, ..... 82 



13. Huyghenian Eye-piece, ....... 83 



14. Ross's Simple Microscope, ...... 91 



15. Gairdner's Simple Microscope, ...... 92 



16. Field's Simple Microscope, ...... 94 



17. Quekett's Dissecting Microscope, ..... 95 



18. Field's Compound Microscope, ..... 98 



19. Highley's Hospital Microscope, . . . . .99 



20. Nachet's Compound Microscope, ..... 101 



21. Smith and Beck's Student's Microscope, . . , .102 



22. Ditto Dissecting Microscope, . . . . 104 



23. Warington's Universal Microscope, . . . . .105 



24. Ditto Ditto, . . . . . .106 



25. Ditto Ditto, . . . . . .106 



26. Ditto Ditto, ...... 107 



27. Ross's Large Compound Microscope, ..... 108 



28. Powell and Lealand's Ditto, . . . . . . Ill 



29. Smith and Beck's Ditto, . . . . . .113 



30. Arrangement of Binocular Prisms, . . ., : . . 115 



31. Nachet's Binocular Microscope, . . . . . .116 



32. Draw-tube with Erector, . . . . . .119 



33. Jackson's Eye-piece Micrometer, . . . . .122 



34. Microscope arranged for Drawing, . . . . . 125 



35. Ross's Achromatic Condenser, . . . . . .133 



36. Smith and Beck's Ditto, ...... 133 



37. Powell and Lealand's Ditto, . . . . . .134 



38. White-Cloud Illuminator, . . . . . . 135 



39. Amici's Prism, ........ 137 



40. Parabolic Illuminator, . . . . . . 139 



41. Fitting of Polarizing Prism, . . . . . .141 



42. Fitting of Analyzing Prism, . . . . . 141 



43. Selenite Object-Carrier, ....... 142 



44. Bull's-Eye Condenser, . . . . . . 143 



45. Ordinary Condensing Lens, ...... 144 



46. Side Reflector, ....... 145 



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