VI 



lADEX. 



Objective 25 



Objects for projection 27 



Organ pipe C') 



Opi'idot-cope 59 



Outline drawings 29 



Overtones 71 



Persistence of vision 139 



Pepper's ghost 84 



Plateau's (fxperiment) .... 56 



Polarization of liglit 127 



Porosity 4') 



Projection with single lens . . 24 

 " '« condenser ... 27 

 '• of large apparatus . 35 

 " Apparatus for verti- 

 cal 40 



Porte Lumicrc, To raake ... 2 



«' " its use .... 24 



Pyrometer 145 



Rainbow 100 



Reactions, Chemical 157 



Rellections 82 



Multiple 83 



Refraction 07 



Resultants 72 



Salicine crystals 134 



Screens 6 



Sciopticons 18 



Silver crystals 53 



Singing llames 64 



Sinuous lines • 69 



Soap bubbles, Persistent . . . 108 



" " Tension of . . . 107 



Solar microscope 100 



♦' spectrum Ill 



Spectacle glasses. To test . . . 132 



Spheroidal form 02 



Spectra, Methods of project- 

 ing 121,153 



Spectrum analysis 119 



" of sodium 121 



" '« '« reversed . 122 



Starch 134 



Stroboscope . 139 



Sympathetic vibrations .... 75 



Thermometer 144 



Total reflection 94 



Tuning forks 67 



Vibrations of strings 59 



«' '« forks 57 



Vision, Persistence of 139 



Water, Decomposed 153 



" Maximum density ... 140 



" Refraction of 97 



" Total reflection in . . . G4 



"Waves in water 61 



Whirliug-table attachment . 77 



Zoetrope 140 



