INDEX 



711 



Dark ground illumination . . . 647-650 



apparatus required 647 



for demonstrating inhomo- 

 genieties in liquids or trans- 

 parent solids 648-650 



Foucault's method 650 



method of striae 647 



Toepler's "Schlieren-Methode" 



647-650 



Darkening room, method 446 



Darkness, avoiding 112 



in opaque projection 175 



of room for sunlight 143 



relative for different projec- 

 tion 443-446 



Davids (Thaddeus Davids Co.) 207 



Davy's Carbon Arc 686 



Daylight vision 175 



Decentering, effects of 53 



Decoration of projection room 



440-441 



Defective vision 659-672 



apparatus required for. . .651-655 

 condenser for demonstrations 



652-653 



demonstrations of 659-672 



lantern slides for. . . .656-666, 671 



source of light for 670 



trial lenses for 651-655 



Delineascopes 



63, 193-196, 310, 312, 355 

 Descartes sine law for refraction 576 



Deschanel's Physics 212 



Diaphragm, effect on cone of 



light 279 



of substage condenser, effect 

 with Koehler method, and 

 with main condenser me- 

 thod of illumination 620 



Diffraction, gratings 631, 644 



images 632 



pattern 644-645 



Diopter, definition 229 



in spectacle lenses 655 



Direct current apparatus 9 



arc, radiant efficiency com- 

 pared with alternating 



69, 474-475, 553-565 



production of 474 



summary for magic lantern . 64-67 



units 475-478 



use of 474 



Dirt on lenses 55 



Distortion, how to avoid in draw- 

 ing 338 



of image 338 



Distribution of light, different 

 forms of arc 562 



Diverging light, to parallelize. . . 274 



Dolbear, Art of projecting 



122, 138, 174, 211, 621 



Double-pole switch. . . 12, 70, 515-517 



Drawing apparatus 319-389 



attachment for ordinary ma- 

 gic lantern 327 



booth 321 



direct current arc lamp for ... 328 



distance, varying for 335 



fastening letter to 375 



from lantern slides 326 



high power 335 



horizontal surface with magic 



lantern 331 



with opaque lantern 332 



house lighting system for .... 339 



landscapes 166 



large objects with low powers 333 



lettering the 374 



microscope for 344, 385 



microscope and lamp at right 



angles 348 



microscope in a dark room . . . 346 

 microscope without ocular or 



substage condenser 334 



models 357 



objectives, 16-8 mm 335 



oculars for 337 



opaque lantern 332 



outfit 350 



house system 343 



with inductor 352 



(Koristka) 323 



with microscope 343~354 



with small currents 343 



photographic camera for. . . . 332 

 projection apparatus for. ... 319 

 projection apparatus, early 



forms 372 



projection microscope for. . . 333 



publication of 373 



radiants other than the arc . . 329 

 range of objects with projec- 

 tion microscope 333 



room and curtains 321 



room, special 320 



shelf 325 



on projection table 326 



