Xll 



LIST OF ILLUSTRATIONS IN THE TEXT 



FIG. PAGE 



40. Diagram of reflecting illu- 



minator . . .128 



41. Camera for photography 



of insects . . .129 



42. Vertical camera for solid 



objects . . ; . 131 



43. Illumination of transpar- 



ent object . . .133 



44. Zeiss' vertical and hori- 



zontal camera arranged 

 for use with planars . 135 



45. Diagram of illumination 



for small anastigmats . 136 



46. Photomicrographic appa- 



ratus arranged for use 

 with small anastigmats 137 



47. Illumination by a parallel 



beam of light . .149 



48. Zeiss' large camera and 



Optical bench . .151 



49. Troughs for light niters . 160 



50. Stops for oblique illumin- 



ation . .' . .177 



-51. Resolution by oblique 



light . . . .178 



52. Wheel stop . , .180 



53. Traviss' expanding stop . 1 80 



54. Diagram of dark-ground 



illumination by central 

 stop .... 181 



55. Davis' diaphragm . .181 



56. Leitz' dark-ground illu- 



minator . 183 



FIG. PAGE 



57. Nelson's dark-ground 



condenser . . .183 



58. Diagram of illumination 



by Watson's parabo- 

 loid . . . .184 



59. Course of rays in Leitz' 



dark-ground illumina- 

 tor . . . ' ; ' . 185 



60. Ernemann's cinemato - 



micrographic appara - 

 tus . . . .188 



61. Objective stop for stereo- 



scopic photomicrogra- 

 phy . . . .194 



62. Vertical illuminator . 195 



63. Prism vertical illuminator 1 96 



64. The Pvosenhain metallur- 



gical microscope . .198 



65. Arrangement of camera 



for micro -metallogra - 

 phy . . . .199 



66. Prism attachment for 



vertical illuminator . 201 



67. Metallographic apparatus 



with inverted micro- 

 scope . . . . 202 



68. Halation . .... 218 



69. Optical bench arranged 



for enlarging and pro- 

 jection . . . .231 



70. Simple enlarging appa- 



ratus . . . .232 



71. Apparatus for living or- 



ganisms . . . 248 



