APPENDIX I. 249 



Messrs. Courtaulds, Ltd. — The use of the microscope in the 

 textile industry. 



Exhibit A . — Samples of artificial silk and cloth, and microscope 

 with sample of cloth under low power, illustrating employ- 

 ment for studying character of textiles. 

 Exhibit B. — Microscope with sample of natural sou pie silk 



stained blue, illustrating identification of fibres. 

 Exhibit C. — Microscope with cross-sections of modern viscose 

 artificial silk, and photomicrographs showing differences in 

 cross-sections of typical artificial silks, illustrating identifi- 

 cation of origin and method of manufacture. 

 Messrs. F. Davidson and Company. — The " Davon " patent 

 super-microscope and optical bench for direct visual observations 

 under high power, large field and great '' depth of focus,'' and 

 embodying a new method of photomicrography. 



Mr. D. Finlayson, F.L.S., and Mr. Raymond Finlayson, 

 F.R.]\r.S., F.Z.S. — The microscope and its uses in seed analysis. 

 Identification and comparison of different species of seeds and their 

 adulterants, by means of a revolving disc attachment to stage of 

 microscope. 



The Geological Survey and Museum (Sir Aubrey Strahan, 

 F.R.S.). — A series of photomicrographs to illustrate the minera- 

 logical constitution and structure of rocks as revealed by the 

 petrological microscope, and specimens to illustrate the mode of 

 preparation of thin rock-sections for microscopical examination. 



Lieut. -Col. William Gifford. — Monochromatic light filters for 

 use in high-power microscopy and photomicrography. F line for 

 visual work, G for photography. 



Messrs. Flatters and Garnett, Ltd. — Photographs of textile 

 fabrics and fibres. 



Mr. J. W. Gordon. — Demonstration of the principles of illu- 

 mination in the microscope, with special reference to: — 



1. Wide-angled lighting. 



2. Narrow-angled lighting. 



3. Wide-angled vision. 



4. Narrow-angled vision. 



Messrs. Hadfields, Ltd. — Photomicrographs of iron and steel. 

 Mr. R. J. E. Hanson, F.R.C.S.— 

 Dyoiitikon {Eye-'piece) Headrest. 



[Applicable to any existing standard microscope.] 

 A sliding headrest is provided, with rubber tubular buffer 

 — to lessen fatigue and mal-orientalion of the eyes and to 

 r>ecure effective retinal adaptation and stimulation of (R 

 and L) visual cortex. 

 A Solution of Visual Puvple. 

 Dr. H. Hartridge. — 



(1) Apertometry by means of the descending light-path. 



(2) Water-soluble immersion medium for use with high-power 

 objectives. 



(3) Critical illumination with immersion condenser, the light 

 source being attached to and forming part of the micro- 

 scope. 



