278 



INDEX. 



SAND - GLASS, Projection of, 



175 



Sciopticon, 6 

 Screens, 86 

 Sheet, Hanging, 88 

 Short-focus lens, 138 

 Signalling, 271 

 Simple regulator, 68 

 Sir David Brewster, 5 

 Sky, Treatment of, 139 

 Slides by contact, 137 

 Spectrum slides, 186 

 Steward's clamp, 56 

 Steward's regulator, 68 

 Superfluous brasswork, 10 

 Supplementary lens, 22 

 Support for lantern, 256 



TABLE of distances, 96 

 Tank experiments, 193 

 Tannin process, 110 

 The Astrometeoroscope, 180 

 The Choreutoscope, 180 



The Galvanometer-slide, 171 



The Kaleidotrope, 179 



The Prism, 182 



" Toilers of the Thames," 



Frontispiece. 

 Treatment of sky, 139 

 Triunial dissolver, 81, 82 

 Triunial lantern, 15 

 Tubes, 76 

 Tyndall's ice experiment, 197 



USE of condenser, 18 



VERTICAL attachment, 12 

 Vortex rings, 191 



WASHBOTTLE, or purifier, 37 

 Water, Decomposition of, 192 

 Wet Collodion-slides, 104 

 Whitewashed screen, 91 

 Woodbury-type process, 113 

 Working the lantern, 76 



