/ 



4 1913 

 A WEEKLY ILLUSTRATED JOURNAL OF SCIENCK^o,, g | |y| us e\ 



" To the solid ground 

 (>t Nature trusts the mind which builds for aye." — Wordsworth 



LOW POWER 



PROJECTION MICROSCOPES 



S,„ e M,„.rr.s: PNC6 COIUpMe £4 14 6 



NEWTON & CO. 0pt kt d "t s h e o H o^^„ t Ki " 6 

 72 Wigmore St., London, W. 



(late of 3 Fleet Street, E.C.) 



STUDY 



THE LENS 



It is the Key to Success in Photography. 



Who can expect to excel who does not understand 

 how to use the diaphragm, the swing back, the 

 rising front, focussing scale, &c, Sec. ? All such 

 questions are lucidly and simply explained in 



" PHOTOGRAPHIC LENSES : 



A SIMPLE TREATISE." 



350 pages, 44. plates, numerous diagrams and 

 illustrations, cloth bound. 



R. & J. BECK, Ltd., L 8 ™™ H ££ 



NEW APPARATUS FOR 



PHOTOMICROGRAPHY 



For use in Horizontal or Vertical Positions. 

 Possessing many New and Important Features. 



NEW EPIDIASCOPE 



A convenient apparatus for ihe Direct Projection 

 in Natural Colours of Mictoscopical Slides, 

 Opaque Objects (such as Book Illustrations, 

 Photo Prints, Diagrams, portions of Plants, Skin 

 Diseases, &c), Lantern Slides, and Spectra. Also 

 for the Projection of Cinema Films of Living 

 Micio-oreanis s, &c. 



LEITZ-EDINGER 



DRAWING APPARATUS 



For the Ditect Projection of Microscopical Pre- 

 parations. Lnsures g.cater accuracy in drajfjng. 



E. LEITZ (London), 



18 BLOOMSBURY SQUARE, W.C. 



The Nesting Season ! 



For Watching Birds 

 The " Folding Minim " 

 is an ideal 

 Ready for use. Naturalist's Binocular. 



It combines the keenest definition, extra 

 wide field, magnification of 5A, and 

 ample illumination ; yet is easily carried 

 in a pocket. Price £7 10 



Full description will he sent post free on request. 



NEGRETTI & ZAMBRA, 



Holborn Viaduct, London, E.C. 

 City Branch: 45 Cornhill, E.C. 

 West End: 122 Regent St., W. 



Ready for placing in case, or pocket. 



