KNOWLEDGE. 



June, 1915. 



CLARKSON'S 



SECOND HAND 



OPTICAL MART. 



TELESCOPES. 



.i4-iii. Wrny.mouni- 

 cit i>n massive oak 

 lath staiul with 

 slictchers, hori- 

 zontal and vertical 

 mov e in c 11 1 s by 

 Hookes joint, 

 slow niotionsjarge 

 fir.dri, 4 astro, ami 

 1 clay f yt'pieces . . £40 O O 

 vj. . in. 5teward, 

 on massive brass 

 pillar am! claw 

 stand (also alia/, stand), tinder, steady- 

 ing roils, vertical rack, dew shade, day 

 evepiece, 3 asiros,. and a toinel eye- 

 piece, mahogany case. .-X great bargain 

 4-in. Bateman. alta/., Tinder, day and 



s aslros, 

 3l-in. Wray, alia/., tinder, vertical rack, 



day and :J astros, 15 lO o 



3}*in. Casella, alia/., i day, 3 astros. 15 o o 



3-in. Wood. 1 :isIio. ;iini 1 ii;w t-Vfpifces . 4 O O 



ManyotheT>, V I • l ; , . s, Diagonals, etc. 



20 o o 



iH 10 o 



MICROSCOPES. 



Zeiss 2 mm. Oil Im- 

 mersion Apochro- 

 mutic Objei:tivc, 



N.A. 1 '40, in slioi I 

 mount 1500 



Zeiss No. 2 Projection 



Eyepiece 112ft 



Watson ' ' Bactil , ' * 

 i eyepieces, i-iii., i.(j, 

 and i/t2 oil immersion 

 objectives, triple nose- 

 piece, nniversal con- 

 denser .. 16 o o 

 Baker '* I). P. H. ** No. 1 , 2 eyepieces, 

 I-eit/ 3 and 7 objectives, triple 

 nosepicce, .Abbe condenser 

 Wat50n " Fram,** eyepiece, spiral 

 .■\bbe with iris, double nosepiece, 2/3 



and 1/6 



Leitz Mb, eyepiece, 3 and 7 objectives, 



double nosepiece. spiral Abbe with Iris 6 lO 

 Beck Small *' London,'* spiral Abbe 



with iris, (loublf nosepiece, 2'3 and 1/6 6 10 

 5wift "Discovery," eyepiece, 2/3, 



1/6, double nosepiece 

 Beck "Star," sliding coarse and micro- 

 meter line adjustments, i eyepiece, 2/3 

 and I '6 objectives, double nosepiece, 

 spiral Abbe with iris, no case 

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

 leading makers). Eyepieces, Double and Triple Nose- 

 pieces, Condensers, Lamps. Spectrnscopes, Microtomes, 



PRISM BINOCULARS 



BY 

 ROSS, ZEISS, 



13 '5 o 



6 IS 



5 >S 



3 S 



' ^_^^ GOERZ, etc.. 



WANTED 



338 HIGH HOLBORN 



(Opposiiv C.rav's Inn R...-m!i 



LONDON. 



Watkins and microscopy. 



»■ r^A*».il^kJ Mlll» s,„-,l,ll, \i,,,.t;,. CI incc: f, DOPULAR 



DONCASTER, 



N ATU R A LI STS 



and Manufacturers of 



Cabinets and 

 Apparatus :: 



FOH 



COLLECTORS OF INSECTS, BIRDS' 



EGGS AND SKINS. MINERALS, 



PLANTS, Etc. 



SPECIAL SHOW-ROOM FOR CABINETS. 



X. /■>'.— Fof Excellence and Su/>eriot-ily 0/ Cabinets 

 ami Ap/>aratus rcjeretuts arc permitted to distin- 

 guished Patrons. Museu/ns, Colleges, ^^c. 



A LARdK STOCK OF INSHCTS. 

 AND BIRDS' li(i(iS AND SKINS. 



SPECIALITY.— Objects for Nature 

 Study, Drawing Classes, &c. 



Birds, Mammals, etc., Preserved and Mounted b> 



First-class Wutkineii tiiie In Nature. 



vm~ All Books and Publications (New and 



Second- hand I on Insects, Birds' H^irs, &c., 



supplied. 



36, Strand, London, W.C 



(P'ive Doors from Charing Cross.) 

 FULL CATALOGUE POST FREb 



LIVING SPECIMENS 



FOR THE 



MICROSCOPE. 



Vol vox globator, Ue^mid^, Diatoms, Spirogyra, 

 Amoeba, Actinophrys, Spongilla, Vorticella, Stentor, 

 Hydra Cordylopohra, Stephanoceros. Melicerta, 

 Polyzoa, and other forms of Pond I^ife. 1s, per tube, 

 with printed drawing, post free. THO^TAS Bolton, 

 Naturalist, 25, Balsall Heath Road, Birmingham. 



MICROSCOPIC SECTIONS 

 ROCKS & MINERALS CUT 



either from Stock or Clients' 

 own Materials. 



r*escripUons and Keimrl-s madt^. Apply — 



JAMES R. GREGORY & Co., 



Mineralogists, Sec 



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



Telephone : Western 2S41. 

 Telegrams: ''Meteorites, London." 



)>'-'-i.dh .\ni;.. tiv.- SLIDES I'-i POPULAR 

 EXHIBITION .1 STUDY. Mm- i- objec 

 Iivv^, .III, I all Actrt-ssorics BOUght, Sold, and 

 Exchanfied. Spxial Cem«-ms, Forceps, Scissors, 



rtc. lor MouiilinK, ric. 

 \Vr\tc }><f Li I-. «'' partUiil.ir ., ■ tat \n ■ mquii erne nts, or call. 



CLARKE & PAGE, 



2:1 TIlHViC^ 



lliilhiini Ciriiis. I.iindon. 



SECOND-HAND DEPARTMENT. 



Microscopes, Telescopes, Spectroscopes, 

 Binoculars, Surveying Instruments, &c., 



BY THE BEST MAKERS AT MODERATE PRICES. 



Lists sent post free on request. 



Surn/i/ii InsliuiiirHli. /:(iii/;iil, I. a Jmu!;,-! and Sold 

 on i'fltiiiiiissn'/t. 



JOHN BROWNING, 



146 STRAND, and 72 New Oxford St.. 



LONDON. 



I'eieuiams : 1 eiepli'tnc 



"AUKS." LONDON !>li C.KK UAR 1 '. 



Established i760 



Stevens' Auction Rooms, 



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



Kvery hRiHAV at Iti.IiU, Sales are held at the 

 Rooms of MiCKOSCOFES AND Slides, Tklescohes, 



SURVEVING InSTKUMENTS, ELECTRICAL AND SCIEN- 

 TIFIC Api'AKATus, Cameras and Lenses, Lanterns 

 AND Slides, Cinematograihs 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 a/l Particulars Post Free. 



Valuations for I'robate or Transfer, and Sales con- 

 ducteil in any pari of the Country. 



ALL KINDS OF BRITISH AND FOREIGN 



Mineral Specimens, 



COMMON MINERAL ORES, and 



CHOICE CRYSTALLIZED SPECIMENS at 



ALL PRICES on view at 



RICHARDS' SHOW ROOMS, 



48 Syjnev Street Fulbam Road. South Kensington. 

 London, S.W. 



riaCI- lASTS HiEl- 



F. WIGGINS & SONS, 



102, 103, 104. Minones, LONDON, E 



Contractors to H.IM 

 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. 9d. Net each; by Post 2s. 



Knowledge Office, Avenue Chambers, Bloonisbury Square, 

 London, W.C. 



Advertisement Rates. 



Discounts for Series of Insertion;, and Ratics for 



Special Positions, when Vacant, on .-VnTHATioN to 



The ADVERTISBMENT Manaoer, 



KNOWLEDGE OFFICE, 



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



