A WEEKLY ILLUSTRATED JOURNAL OF SCIENChN 



" To the solid ground 

 Of Nature trusts the mind which builds for aye." — Wordsworth. 



[JJ ^CES&WEJG HTSI 



John J. Griffin & Sons, L 



KEMBLE ST., KINGSWAY 

 LONDON, W.C. 



Scientific Instrument makers. 



The GRAY-BURNSIDE 



MOTOR - GYROSTAT 



With 10 attachmenWfor demonstrating all the pro- 

 perties and practical applications ot the Gyrostat. 



Dest riplive Booklet, with Prices, on Application. 



Gyrostatic Pendulum. 



GRAY'S GYROSTATIC MODELS 



Prices on Application. 



REYNOLDS &, BRANSON, Ltd. 



GRAND PRIX AWARD, TURIN, 1911. 



SOLE AUTHORISED MAKERS OF 



STROUD & RENDELL SCIENCE LANTERNS. 



The "University" Lan- 

 tern, with Russian iron 

 body, sliding baseboard, two 

 superior objectives, plane 

 silvered mirror " A," which 

 is moved by a knob causing 

 the rays to be reflected 

 upw ards lor the projection 

 of objects in a horizontal 

 plane, condensers 4! in.diam., 

 prism with silvered back 

 which can be used at " C,' 

 or as an erecting prism 

 in mount " D," lime-light 

 burner, slide carrier. Price 

 complete in travelling case, 

 without reversible adjustable 



table "B." 



Ditto, ditto, with "Phoenix" Arc Lamp 



Reversible adjustable table " B" for supporting apparatus, 

 The " College " Lantern, without adjustable table, 



lime-light burner complete 

 Ditto, ditto, with " Pluenix " arc lamp ... 



P.,1 





Mechanical Models for tea 



£10 7 6 

 II 15 



8 2 6 



9 10 



7 6 



for spectrum with support, for either lantern . 



riser and analyser 2 



Catalogues post free. 

 Optical Lanterns and Accessory Apparatus. 223 pages. 

 1 Abridged List of Chemical Apparatus and Chemicals. 44 pages. 

 ' ng Building and Machine 



Con 





14 COMMERCIAL, STREET, L.EEDS. 



THE NATURALIST'S 

 FIELD-GLASS. 



The " Folding Minim " 



Ready /ot 



is an ideal Binocular 

 for Nature Study. It 

 combines the keenest definition, extra 

 wide field, magnification of 5£, and ample 

 illumination ; yet is no larger than a cigar 

 case, and is easily carried in a pocket. 



Price, in pocket case, or leather sling case. £7 10 



NEGRETTI 8- ZAMBRA 



Holborn Viaduct, London, E.C. 

 City Branch : 45 Cornhill, EC. 

 West End : 122 Regent St., W. 



Illustrated 

 price lists of 

 'BINOCULARS' 



Ready for placing in case, or pocket. 



