LIST OF TEXT ILLUSTRATIONS 



FIG. PAGE 



1. Mixed-Gas Jet and Stand, by Newton & Co 4 



2. Mixed-Gas Jet, by Beard — as used by the Author. . . . 4 



3. Mixed-Gas Jet, by Beard, affixed to Author's Stand ... 4 

 3a Ross "Radiant" Mixed-Gas Jet on Stand 4 



4. GwYER Mixed-Gas Jet 4 



4a. Blow-through Jet, by Beard ........ 7 



5. Beard's Regulator — Interior 9 



6. Beard's Regulator — Outside Appearance, Attached to Gauge . 9 



7. Heliostat, by Baker .......... ii 



8. Heliostat, by Watson, after Dr. Johnson Stoney . . . . 11 



9. Diagram of Apparatus Arranged for Low-Power Photo-Micrography 14 



10. Use op Condenser in Low-Power Photo-Micrography . . .15 



11. Camera Portion of a Simple Form of Apparatus for Low-Power 



Photo-Micrography 24 



12. Railed Sliding -Portion to Contain Arrangement as given in Fig. ii 24 



13. Apparatus Complete .......... 26 



14. Mechanical Stage for Holding Slips for Low-Power Photo- 



Micrography ........... 26 



15. Diagram — One Position of Apparatus for Photographing "Culture- 



Tubes" 27 



16. Diagram — Another Position op Apparatus for Photographing 



"Culture-Tubes" . 27 



17. Details for Conveniently Holding Limelight when Photographing 



" Culture-Tubes " 29 



18. Arrangement of Simple Kind for Enlarging Negatives on Bromide 



Paper 29 



19. Stand for Photo-Micp-ography, by Baker 49 



b 



