INDEX 



447 



PHO 



RIN 



Photochromoscope, 436 



Photographic slides, 136 



Photography, 247 ; colour, 435 



Physiological demonstration, 230 



Piles of glass for polarising, 340, 

 345, 351 



Pillar-stands, 174 



Pinhole, experiments with, 3, 6 



Place's lime-turning arrangement, 

 64 



Plane mirror, 175 



Plaster surface as a screen, 124, 

 200, 208 



Plateau's experiments, 226 ; soap 

 solution, 325 



Plates, perforated, for diffraction, 

 337 



Plug dissolving tap, 108 



Polarisation, plane, 349 ; circular, 

 362 ; rotary, 365 ; of heat, 393 



Polarised light, 349 ; and common, 

 352 



Polarising apparatus, 338 



miscroscope, 201 



Polarity, magnetic, 394 



Pond life, exhibiting, 204 



Portable screens, 126, 131 



Prazmowski's prism, 340 



Precautions against explosions, 55, 

 59 



Precipitations, 243 



Preparation of gases, 73 



Press for straining glass, 360 



Pressure of gas in bags, 53, 58 ; in 

 cylinders, 84 



Pressure-boards, 44, 55 



Pressure-gauge for testing gas- 

 cylinders, 85 



Pressure-regulators, 86 



Pringle's cut-off for jets, 117 



Printed diagrams, utilisation for 

 the lantern, 414 



Prisms, action of, 4, 281 ; achro- 

 matic, 291 ; compound and 

 direct, 293 ; dispersive, 175, 282, 

 293 ; double-image, 349 ; Fres- 

 nel's, 332, 376 ; Nicol, 339 ; 

 Ahren's improved, 345 ; polaris- 

 ing, 339, 344, 349 ; wedge-form, 

 $81, 286 



Projection : definition, 1 ; of ap- 

 paratus, 212 ; by shadow, 216 



Projection microscope, 179, 431 



Propagation of waves, 321 



Proportions of gases burnt, 52 



Pulse, movement of, 233 



Pumice safety chambers for jets, 

 93 



Purifying oxygen, 78 



QUARTER-WAVE plates, 364, 367 

 Quartz in polarised light, 370, 372 



HACKWORK slides, 142 



Eadiant, the, 34 



Radiant heat in spectrum, 391 



Radio-micrometer, the, 393 



Rainbow, the, 289 



Rain-effect slide, 143 



Rays form images, 1 ; management 



of, 11 



Reactions, chemical, 243 

 Reade's iridescope, 331 

 Recomposition of light, 285 

 Reed apparatus for projecting 



Lissajous' figures, 262 

 Reflecting mirror, use of, 256, 277; 



polariscopes, 232, 237, 261, 338, 



346 

 Reflection of light, 274 ; angle 



doubled in, 277 ; total, 279 

 Refraction, 4, 278 ; by prisms and 



lenses, 281 ; double, 349 

 Refulgent petroleum lamp, 37 

 Registration of slides, 104 

 Regulators for gas-cylinders, 86 

 Reinold and Riicker on films and 



currents, 408 

 Retorts for oxygen, 75 

 Reusch's artificial quartz, 382 

 Reversed spectrum lines, 310 

 Revolving mirrors, 270 ; lenses, 



270, 400 ; polariscope, 371 

 Rhigoline for O.-H. light, 95, 100 

 Rings, Newton's, 328, 353; wire 



for soap-films, 225, 326 

 Rings and brushes in crystals, 



76 



