KNOWLEDGE. 



April, 1915. 



CLARKSON'S 



SECOND-HAND 



OPTICAL MART. 



TELESCOPES. 



4$>in, W'rny.ni 



r i : i massif c oak 



lath siaml with 



hers, liori- 



7oni.il and vertical 



moi ;n t s by 



I [i ioke's joint, 

 slow mi i 



in dei . .1 astro, ami 

 i .i.i\ ' \ epiei es £-40 

 4-in..full,Nejpretti 

 & Zumbra.ili.i/.. 

 finder, 1 day, ; 



. ase 

 :.'..in. Baker, altaz., hoi izontal and vertical 



motions, findei . da} ami .■ astros, 

 1 -in. Casella, altaz., 1 daj . ■ astros. 



Steward, on altaz. with equatoi ial 



rcles), 1 day, 2 astros. 

 Wood, 1 astro, and 1 day eyepie* es 



Mans ■'' 



Also Eyepieces, Finders, Diagonals, etc. 



MICROSCOPES. 



Ituctil , 



1(1 



15 is 



14 14 o 



I.! 15 



IS 



MICROSCOPY. SECOND-HAND DEPARTMENT. 



Watson 



eyepieces, 1 -in., 1/6, 

 oil immersion 



oltjccm 1 triple 1 



piece, universal con- 

 denser . - 

 \\ ;it<on ' ' Edinburgh 



M," , t/6, i/j o.i., 



piei es, triple 



ei '■, and AMie 



Kcck Large "London," 



; eyepii ■ 



and 1 i.j ■■!' immei sii >n 



. tives, triple nosepiece, spiral Abbe 



and iris, me< hanical stage, as new 

 Baker "D.P.H." No. 1, 2 eyepieces, 



Leii/ ; ami 7 objectives, triple 



n -■ piece, Vbbe condenser 

 Watson "Fram," eyepiece, spiral, 



\ i- ; .' mble nosepiei e 1 \ 



and 10 . . 



Leitz Mb, eyepiece, 3 and 7 objectives, 



d< mbli piral A h and ins 



Heck Small "London," spiral, \Ki" 



and iris, double nosepiece, 2/3 and 1/6 

 Sw ift " Discovery," eyepiece, 2/3, 



1 6, double nosepiece .. 

 Beck ".Star," sliding coarse and micro- 



meter line adjustments. 1 eyepiece. 2/3 



and 1/6 objectives, di mble n use piece. 



spiral Abbe and in-, no case 3 5 o 



Many others. Also Objectives (a large stock by all the 

 ending makers), Kyepieces. Double and Triple- Nose- 

 ,■ . 1 ■■ . ( Condensers, Lamps, Spectroscopes, Miootoines, 



PRISM BINOCULARS 



BY 

 ROSS. ZEISS, 

 GOERZ. etc., 



FOR SALE 



AND 

 WANTED. 



338 HIGH HOLBORN 



(I Ipp site Gray's l"n Road), 



LONDON. 



SPECIALLY ATTRACTIVE SLIDES 

 FOR POPULAR EXHIBITION V STUDY. 



Zoology, Marine and Freshwater. 



Unique preparations, wit/tout pressure^ in their natural 

 form and beauty foi Dark Ground (■>■ transparent), 



1 ,v\, M,-<it4s<r, Polyzoa, with their glorious .uia\ 



■ >i tentacles; ffofothurians with wheel plates, etc.; ■> 

 ■ in of th< curious Salfa and other Tunicata ; youn 



developing in their eggs ; the celebrated 

 (W ; also the Radiolarian Spheerozoum^ the "Volvox of 

 the sea," etc., etc. 



Insects and Parts. I.arvaof /7«;>/ ( -,/<,'/i«/ 

 (also for polariscope). Superb tongues of the rare 

 Sylvan Wasp and Hornet, also piercing organs of the 

 Gaafly, etc.) etc. 



Special Cements, Forceps. - 1 etc, etc., for 



Mounting and Dissecting. 



SECOND-HAND 

 INSTRUMENTS, 

 OBJECTIVES, &c. 



NEW LIST 



NOW READY. 



Post free on request. 



To Beginners."— Expert advice freely given 



on ^election of suitable equipment; much time and 

 needless expense can thereby be saved. Write 01 call. 

 WuNTFD Microscopes, Objectives, etc., or whole 



Outfits purchased for Cash. 



EXCHANGES M* 



CLARKE & PAGE, 



25, Thavies Inn, Holborn Circus, LONDON. 



LIVING SPECIMENS 



FOR THE 



MICROSCOPE. 



Vol vox globator, Desinids, Diatoms, Spirogyra, 

 Amceba, Actinophrys, Spongilla, Vorticella, Stentor, 

 Hydra Cordylopohra, Stephanoceros, Melicerta, 

 Polyzoa, and other forms of Pond Life, 1s. per tube, 

 with printed drawing, post free. Thomas Hoi. ton, 

 Naturalist, 25, lialsall Heath Road, Birmingham. 



MINERALOGY AND 

 GEOLOGY. 



JAMES R. GREGORY & Co., 



Mineralogists, &c. 



Are in .1 better position than ever for supplying 



Collections of Minerals, Fossils & Rocks, 



A* they hav 



ateriaj. 



LISTS AS USUAL. 



139, Fulham Road, South Kensington, S.W. 



Tele 

 Telegri 



Western '2X41. 



1 Meteorite:.. Londo 



Microscopes, Telescopes, Spectroscopes, 

 Binoculars, Surveying Instruments, 4c, 



BY THE BEST MAKERS AT MODERATE PRICES. 



Lists sent post free on request. 



Scientific Instruments Sought, Exchanged and Sold 



on Commission. 



JOHN BROWNING, 



146 STRAND, and 72 New Oxford St.. 



LONDON. 



Telegrams : 



'AUKS," LONDON. 



Telephone 

 884 GERRARD. 



Established 



Stevens' Auction Rooms, 



38, KING ST., COVENT GARDEN, LONDON, W.C. 



Every FRIDAY at 12.30, Sales are held at the 

 Rooms of Microscopes and Slides, Telescopes, 

 Si rveving Instruments, Electrical and Scien- 

 riFic Apparatus, Cameras and Lenses, Lanterns 

 and Slides, Cinematographs and Films, in great 

 variety, Lathes and Tools, Etc. 



Goods may be sent for inclusion in early Sales. 



Settlements made one week after disposal. 



Catalogues and all Particulars Post Free. 



Valuations for Probate or Transfer, and Sales con- 

 ducted in any part of the Country. 



FOR ALL KINDS OF EDUCATIONAL 



Mineral Material, 



COMMON ORES, and SELECT CRYSTALLIZED 

 SPECIMENS, at ALL PRICES. 



G. H. RICHARDS & Co., 



Dealers 'n all kinds of British and Foreign Mineral 

 Specimens. 



PRICE LISTS FREE. 

 4£ Sydney Street Fulham Road, South Kensington 

 London, S.W. 



F. WIGGINS & SONS, 



102, 103, 104, Minories, LONDON, E 



Contractors to H.M. 

 Government. 



FOR 



LAMPS. 



STOVES. 



VENTILATORS, 



ELECTRICAL WORK 



AND ALL PURPOSES. 



Largest Stock in the World. Tel. No. 2248 Avenue. 



Printer of 

 ' Knowledge. 



JOHN KING, 



Uxbridge, Southall, and Ealing, 



T s favourably equipped for the PRI NTI NG of 



*■ Scientific Hooks, Brochures, Catalogues, &c, ami 

 will be pleased to submit estimates. 



Address all Communications to 



213, UXBRIDGE ROAD, EALING, LONDON, W. 

 "Phone: 1144 Ealing. 



Binding Cases for Knowledge Volume, 1914. 



IN BLUE CLOTH, WITH GILT DESIGN AND LETTERING. 



9d. net each : by post, 



Knowledge Office: AVENUE CHAMBERS, BL00MSBURY SQUARE, LONDON, W.C. 



A most acceptable Girt at any time. 



KNOWLEDGE VOLUME FOR 19 14. 



Container; 440 Pages m'Ii 425 Illustrations, many being Full Page Plate'.. 

 ... .i in Blue Cloth. <dlt Design and Lettering, 15.- net. post free within the United kingdom. 



Publishing Office: AVENUE CHAMBERS, BLOOMSBURY SQUARE, LONDON, W.C, or through any Bookseller. 



