708 



OPTIC PROJECTION 



Bausch & Lomb Optical Com- 

 pany, cuts loaned by, 35, 60, 90, 

 91, 127, 184, 187-189, 191-192, 

 304, 306-308, 356, 358, 404-405 

 ref. in text, 80, 190, 286, 459, 

 512 



Bayley 9, 217 



Bench, home-made optical 288 



Beseler, (Chas. Beseler Co.) .... 94 



Blackboard, lighting 448-452 



Black stain for tables 289 



Blackened, apparatus. . . .7, 242-246 



objectives 246 



Block with lead sheets 292 



Blocks for apparatus 291 



Blondel, intrinsic brilliancy de- 

 termination 564-566 



Blood corpuscles, demonstration 



of 227 



"Blow" said of a fuse 83 



Blow-through jet 105 



Botanical Gazette 289 



Botanische Zeitschrift 289 



Boyle's law and camera. . 104, 129,675 



Box to cover switch 517 



Break in circuit 514 



Briggs* lantern slides 673 



Brilliancy, of screen image 610 



intrinsic. . .564-566, 613-615, 619 

 limit of, with projection micro- 

 scope 618 



reduction by substage con- 

 denser, amplifier and ocular 61 8 



sunlight most brilliant 619 



British lantern slide 200, 203 



British photographic society .... 217 

 Brown & Sharp's wire gauge .... 502 

 Bulletin of the Bureau of Stand- 

 ards 547, 566 



Bunsen burner 125 



Burner, blow-through type 105 



lime light 105 



mixed jet 107 



roars or hisses 115 



Burning out a fuse 519 



Burning point or focus 578 



Burr, Geo. L 673 



Bushings for small carbons in 

 large lamp 80 



Camera, adjustable back 212 



and plate-holder 382 



enlarging, reducing, copying 210 

 hinged baseboard 211 



landscape drawing 166, 167 



lantern slide making 209, 213 



printing by projection 378 



spectrographic 643 



tilting 212 



vertical 382 



Camera obscura, history . . . 673-575 



Candle-power, and current 559 



current and size carbons 



87, 248, 551-552 

 direct current inclined carbons 556 



formula for finding 613 



of arc lamps 553-565 



from kilowats 558 



lime light, relative 100 



petroleum lamp 125 



power consumption 561-562 



rectifier 558-559 



rectifier 



inclined carbons 557 



right-angled carbons. . . . 558 



sun 138 



variation with current . . . 553-556 

 watts, alternating current, 



inclined carbons 557 



right-angled carbons 557 



right-angled carbons 556 



Capacity of gas cylinders 104, 128-129 



Capacity meter 103 



Carbon arc lamp for spectra. ... 628 



Carbons, adjusting 252 



alternating and direct cur- 

 rent with 340 



arc with 10 and 20 amperes . . 249 

 arrangement of 543, 545, 548, 

 inclined; right-angled, 342, 507, 

 538, 540-542 



arrangement in micro-pro- 

 jection 284 



bad position 50 



composition and movement. 72 

 converging, with alternating 



current 564-565 



cored and solid 250 



correct position 49 



efficiency of different ar- 

 rangements .560-561 



electrodes 539 



feeding with alternating cur- 

 rent 74 



feeding on house circuit 342 



feeding with small arc 87 



house system 341 



image on screen 251 



