December, 1910. 



KNOWLi:i)r, 



AITCHISON & Co. 



Opticians to H.M. Government. 

 The only makers in the world who have 

 succeeded in making 

 Prism Binoculars magni- 

 fying 25 diameters. 



PRICE £12 10 O 



with best solid leather case. 

 With central foc'jssiiv.; tnnlion £1 extra. 



Every Glass Tested at the 

 BRITISH GOVERNMENT 

 LABORATORY AT KEW, 

 and Certificate of Power, Defi- 

 nition, &c., signed by Dr. 

 R. T. Glazebrook, F.R.S., 

 the director, is given with the 

 Glass to Purchaser. 



The Night and Day Marine Wide Aperture Prism Glasses. 



X 9 MAGNIFICATION £6 10 x 16 MAGNIFICATION £8 10 



X 12 MAGNIFICATION £7 10 x 20 MAGNIFICATION £10 10 



X 25 MAGNIFICATION £12 10 



With cti::..il 1.. '.i-:!;.; :"":!■ '■■■ «1 i-ira. 



Prices incUtde Beit Solid l..allier Sliiig La-e. postage and packing to any 



part of the World. 



Price List n/ l^tisi'i ami oilit-r Biitociiiar s I'cst Frct: 



AITCHISON &, Co. 



Opticians to H.M. * t..S.4. (iovts.. 



428, STRAND, and Branches, LONDON. 



■> TRADE MARK. 



NE W BOOKLET 



PHOTOMICROGRAPHY' 



Containing a discussion of ihe ccnsiderations govern- 

 ing the Contrast obtained in the Photography 

 of Microscopic Specimens. 



Free oil application, ciiclo.'iiiiii Id. stamp 



r',,r pi,.-itai:c. t,< 



^ WRATTEN & WAINWRIGHT, Ltd.. CROYDON. 



@ 

 8 



I 



BEFORE PURCHASING A MICROSCOPE THE 



WINKELj 



STANDS AND OBJECTIVES SHOULD BE SEEN. 

 Catalogue post free from Sole Agents, 



H. F. ANGUS & Co., 



I 83, WIGMORE STREET, LONDON, W. | 



"^ 



H. K. LEWIS, 



PUBLISHER & BOOKSELLER, 



136, GOWER STREET, and I nNnHN W R 



24, GOWER PLACE, . . . L"''""''- "■"■ 



Neu- liook riepartnient. shoiviiii; .Main Entrance from (lower Street. 



Cotnpletest Stock of Text Books and 

 Recent Scientific Literature. 



Asent f(ir the F.vaminatiiin I'aptrs m the Lni^t^sit^ ii( Liimlnii. 

 Orders by Post promptly attended to. 



BOOKS IN ALL DEPARTMENTS OF LITERATURE. 



I BOO 



L 



■I'lHtlCAVIT. LOM.OX." 7V/V/i/;',».-,- -111.7-1 'r NT KA 



BAUSCH & LOMB'S 



CELEBRATED 

 MICROSCOPES. 



New and Improved Models. 



H H .s L.ABOkATOKV MODtL (as li-inedl 

 v\ilh ;;-in., ,\-in., and j^-in. (oil innuersion) objectives, 

 ■J eye-pieces, screw-out substage, with Abbe con. 

 l-.-nser, and triple dust-proof nosepiece, in cabinet. 



£13 2 6 



B B H 8 LARGER LABOKA- 

 TORY MODEL, as above, but 

 with screw-out ii'tii swius-dowu 

 ■.ab-L.^e £18 4 6 



^ 



li H 4 MODEL, with =-in. and 



.'-111. oi.jcctivcs. 2 eyepieces, :rr.'\ 

 ■ irciilar (iii>t-proof nc'sepicce. 



£5 12 6 



.Microtomes, C e n t r i t u g^es. 

 Photo - micrographic anJ 

 Projection Apparatus, 

 Precision Laboratory- 

 Glassware, &c. 



)i^pc>,lion coidially invited at om 

 how-Rooms or List.s sent po!>t fret-. 



^ ^ THE BAUSCH & LOMB OPTICAL Co., 



■i^^^^^^^^X C.",;r.,.tr:s .:• Urin,/, an./ F..„i,., <:,.r.-.„„:„,/s. 



19, THAVIES INN, HOLBORN CIRCUS, 

 LONDON, E.C. 



Our Microscopes, etc.. may be obtained 



Tkapt: M.\Kk-, 



through any Optician. 



ned^^ 



