INDEX 



ABE 



ABERRATIONS of lenses, 7 ; of con- 

 densers, 19, 21 ; of objectives, 25 

 Absorption of colour, 299, 305 ; 

 lines in spectrum, 310 



Accessory lantern apparatus, 145 ; 

 for scientific work, 170-8 (see 

 also Subjects) 



Achromatism, 291 



Achromatic lenses, 25 



Acoustics, 247 



Acoustic figures, 252, 255, 266; 

 pencils of light for, 257 



Actinic rays, effect of, 316 



Adjustment of a jet, 50 ; of the 

 light, 115, 214 ; kaleidoscope, 

 146 ; microscope, 197 



Ahren's polarising prisms, 345; 

 reflecting polariser, 346 



Air-films, colours of, 328 



Air, vibrations in, 268 



Airy's spirals, 379 



Alternate current, danger of, 165 



Alum cells, 150, 183, 207, 328, 

 331 



American lanterns, 155, 168 



Ampere's current experiments, 403 



Amplifying image in the micro- 

 scope, 186 ; by aye-pieces, 188 



Analysers for polrvriscopes, 339 



Analysis, spectrum, 304 



Anomalous dispersion, 295 



BOD 



Antiseptics, demonstration of, 245 

 Aphengescope, the, 147 

 Apochromatic objectives, 194 

 Apparatus, projection of, 212 

 Arc, projecting the, 410 

 Arc-lamps, 40, 162, 425-431 ; for 

 spectrum experiments, 159, 305 

 Argand lamps, 34 

 Atwood's machine, 220 

 Axes, polarising, 364 



BAILEY, Mr. G. H., and zirconia, 70 



Bands of colour in soap-films, 327 ; 

 in selenite, 354 ; quartz, 373 



Barton's buttons, 336 



Beads, silvered, for acoustics, 252 



Beams and pencils of rays, 172, 

 257, 276 



Beard's regulators, 86, 88 



Bells, vibration of, 249 



Benzoline for O.-H. light, 100 



Billet's lenses, 334 



Bi-prism, Fresnel's, 332, 376 



Bi-quartz effects, 372 



Bi-unial lanterns, 109; experi- 

 mental, 157 ; vertical, 169 



Bleaching, 244 



Blood-pressure, 239 



Blow-through jets, 47 



Body of a lantern, 14, 111 



