VI. 



KNOWLKDGK. 



May, 1915. 



CLARKSONS 



SECOND-HAND 



OPTICAL MART. 



TELESCOPES. 



\\ raj ,m 

 ed on massive oa! 



I. itl. stand ^ i' h 

 siren hei . hori 



.'. nii.i! ..■ 



! I ike's i " i n t , 

 sit ^\ motions, .■■ 



i%. i da) eyepiw es i-4" 

 l,Negrettl 

 & Zambru.ilt.i/ , 



■ 



day, 



■ ■ i ■-. . in i .im 



3J-in. Baker, alts 



i ■ ■•■. 

 Casella, altaz., i day, .- ;isim>. 

 i in. Steward, on altaz. with equal irial 



irclcs), i day, a astro* 

 i<in. Wood, i astro, and ■ da) eye] 



,•111, " mru, i it 31 1 u. .lllll | 



M.inv ■[ ii.'i -. \ | s , , |. ^ e pi, 



17 loo 

 1500 



I I 10 o 

 400 



MICROSCOPES. 



I inders, 1 diagonals, etc. 



\\ .it son ' " Bactll . ' ' 

 a ej epiei !-■-, i*in., 1 6, 

 1 1 is oil immersion 

 objectives, ii iple n 

 piece, universal con* 

 denser . , l6 



Watson '• Edinburgh 



H," 1 I'M.. 



eyepieces, iriple 



isepiece, and ^bbe 15 150 



Keck Large "London," 



eyepn 1/6, 



and 1 14 <>ii immei sii in 



■ ■ lives, triple nosepiei c, spiral . 

 and iris, met hanii ,il stage, as new 

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



Leitz _; ami - objectives triph 

 nosepii ce, \: be 1 indenser 

 Watson " f'ram," eyepiece, spiral, 



Abbe and iris, 1 ml :piece, 2/3 



and i/6 



Leitz lib, eyepiece, ; and 7 objectives, 

 double nosepiece, --pii.it Abbe and iri 

 Beck Small "London." spiral, Abbe 

 ami tris, double n ind 1/6 



Swift "Discovery," eyepiei ■ 



piece 

 Beck " Star,' ' slidi coai se and mi ro 

 meter line adjustments, 1 eyepiece, 2 

 and i 6 obj ctivi ■ ,. iuble nosepiece, 

 spiral Abbe atn i ii 1-. ni 1 . ase 

 M--.h\ others Also Objectives (a large stoi k by all the 



■ m.ikr -i,l, £y, pj, l 1 . .;,. ,,, ; ] , ,,,,,- Nose- 



!'"■' es, < ondensers, I amps, Spo troscopes, Microtomes, 



PRISM BINOCULARS 



14 14 



6 15 

 6 10 

 6 10 



S IS 



3 S 



BY 

 ROSS. ZEISS. 

 COEItz, etc., 



WANTED. 



338 HIGH HOLBORN 



(Opposite Gray's Inn Road), 



LONDON. 



Watkins 



AND 



DONCASTER, 



N ATU R A LI STS 



and Manufacturers of 



Cabinets and 

 Apparatus :: 



FOR 



COLLECTORS OF INSECTS. BIRDS' 



EGGS AND SKINS. MINERALS. 



PLANTS. Etc. 



Lovers of Birds who wish to 

 encourage them to nest in their 

 gardens or shrubberies should 

 apply for our Price List of Nesting 

 Boxes. 



A LARUE STOCK OF INSECTS, 

 AM) BIRDS' ECltiS AND SKINS. 



SPECIALITY. Objects for Nature 

 Study, Drawing Classes, &c. 



Birds, Mammals, etc.. Preserved and Mounted by 

 First-class Workmen tine to Nature. 



|9~ All Hooks and Publications on Natural 

 History supplied. 



36, Strand, London, W.C. 



{Fi\e Doors from Charing Cross.) 



CATALOGUE POST F/?fcfc 



LIVING 



SPECIMENS 



FOR THE 



MICROSCOPE. 



Vol vox globator, JJestnido, Diatoms, Spirogyra, 

 Amreba, Actinophrys, Spongilla, Vorticella, Stentor, 

 Hydra, Cordylopohra, Stephanoceros, Melieerta, 

 Polyzoa. and other forms of Pond Life, Is. per tube, 

 with printed drawing, post free. Thomas Bolton, 

 Naturalist, 25, Halsall Heath Road. Birmingham. 



MIN 



FOR ALL PURPOSES 



[Nl 1 I DING 



Experiment, Wireless, Incandescent Mantles, 

 Radio-Active, Steel Making, &c, <Xc. 



Apply /„ 



JAMES R. GREGORY & Co., 



Mineralogists, &c, 



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



'I elephone : Western 284 I 

 Telegrams: "Meteorites, London. 



MICROSCOPY. 



Specinlh An, .mi 

 EXHIBITION 

 tivi and ..II A 

 Exchanged. 

 eti 

 Write fo 



w SLIDES 1 POPULAR 



STUDY. Mi' ' pes, Objec- 



Bought, Sold, and 



S|„-, ml 1 », Forceps, Sci 01 



etc., for M ting, i ti . 



/ 1 ' ■ ■ partit i/l " . in: in rsquirtments, of call. 

 CLARKE & PAGE, 



2'A Thuvies Inn, Holborn Circus, London, 



SECOND-HAND DEPARTMENT. 



Microscopes, Telescopes, Spectroscopes, 

 Binoculars, Surveying Instruments, &c, 



BY THE BEST MAKERS AT MODERATE PRICES. 

 Lists sent post free on request. 



Scientific Instruments Bought^ Excliangtd and Sold 



on Cot/intissii'/i. 



JOHN BROWNING, 



146 STRAND, and 72 New Oxford St.. 



LONDON. 



Telegrams: 



"AUKS," LONDON. 



Telephone 

 S24 GKRKAKI). 



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, 

 Surveying Instruments, Electrical and Scien- 

 tific 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 (or Probate or Transfer, and Sales con- 

 ducted in any part of the Country. 



Minerals, Rocks, Fossils, Metallic 

 Ores, Rough Precious Stones, &c. 



A Large As 

 on view 



id at all pi 



all pat 



I nspi i til 'ii 



.rid always 

 nvited. 



Crude Mineral lor Chemistry Students 



and Technical Schools. 



Single Cystals and Teaching Specimens in Great Variety. 



RICHARDS' SHOW ROOMS, 



48 Sydney Street Fulham Road. South Kensington. 

 London, S.W. 



fRICE LISTS tREE. 



F. WIGGINS & SONS, 



102, 103, 104, Minories, LONDON, E. 



Contractors to H.A1 

 Government. 



LAMPS, 



STOVES. 



VENTILATORS. 



ELECTRICAL WORK 



AND ALL PURPOSES. 



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



BINDING CASES 



FOR 



Knowledge Volume, 1914. 



IN BLUE CLOTH, WITH GILT DESIGN 



AND LETTERING. 



Is. 96. Net each ; by Post 2s. 



Knowledge Office, Avenue Chambers, Bloomsbury Square, 

 London, W.C. 



Advertisement Rates. 



Discounts kor Series ok Insertions and Rates for 

 Special Positions, when Vacant, on Application to 



The Advertisement Manager, 



KNOWLEDGE OFFICE, 



AVENUE CHAMBERS, BLOOMSBURY SQUARE, LONDON, W.C. 



