KNOWLEDGE. 



January, 1915. 



LANTERN SLIDES. 



Plants, Plant Associations, Trees, llaromals, &c.. 

 Birds, Insects, Spiders, Sc, Water, Ueology, Palxnn. 

 lologv and Prehistoric Antliropology. .Sale or hire. 

 Lists'fiec. St.^te siil.ject. J. Holmes. 45, Higii 

 .Street. Rochester. 



FOR SALE. 



Five-inch REFRACTING TELESCOPE ly Steward 

 equ.itoriallv mounted on iron colimiii, clock-tlnven ; 

 declination and hour circles divided on metal and titled 

 with microscopes: diagonal eyepiece; complete, with 

 all tittings, and in first-rate rondition ■. originally cost 

 ilSO. 



TRANSIT INSTRUMENT iv Steward, 2J-inch aper- 

 ture; di.i'4"iMl i V. |.).-i ,■ ; with all fittings, and in perlect 

 conditiiiii; "i i;:ni.ilU' '"-t J,30- 



REFRACIING TELESCOPE \<v Gilbert, 2*-inch object 

 glass, pillar and claw table stand, with finder, .altitude 

 and azimuth rack motions, one erecting and si.\ celestial 

 eyepieces of powers ol 50, 90, 130, 270, 400, and 472 

 very good condition ; in mahogany case. Apply to 

 Miss J.ACSON, Bottville, Kingsbridce Devon 



CLARKSON'S 



SECOND-HAND 



OPTICAL MART. 

 TELESCOPES. 



^■in.Wray, mount- 

 ed on massive oak 

 alh stand with 

 '.Lretcliers, hori- 

 zontal and vertical 

 movements by 

 Hooke's j o i li t , 

 slow motions, large 

 finder, 4 astro, and 

 I day eyepieces - £40 O O 

 4-in..fiill,Negretti 

 & Zambraalta^., 

 finder, i day. 3 

 .istros. , in case ■• . . 25 o o 



3i-in. Baker, on altnz. stand, horizontal 

 and \ertical motions, finder, day and 

 2 astros. .. .. .- ..17100 



3i-in. Dollond, on altaz. stand, finder, day 



and 2 a^tros. .. ;.. 12 10 O 



3-in. Steward, on aliaz. with equatorial 



(undivided circles), i day. 2 astros. I I lO o 



3-in. Wood, I astro, and 1 day eyepieces . 4 o O 



Many others. Also P^yepieces, Finders, Diagonals, etc. 



MICROSCOPES. 



17 '7 



'5 IS o 



Watson " bJinburgh 

 Student's ' ' Hinocu- 



lai, ^ eyepieces, 2-in.. 



i-iii., A-in., pnlari- 



scope, and case 

 Watson '* Edinburgh 



H/' 2/3, i/D, 1/12 o.i.. 



2 eyepiei^es. triple 



nosepiece, and Abbe 

 Baker"D.P.H." Stand, 



triple nosepiece, Abbe, 



and case 

 Beck*s Large "London" Handle Model, 



spiral, Abl.ie and iris, triple nosepiece, 



2 eyepieces, 2/3 and 1/6, as new. 

 Watson " Fram,*' eyepiece, spiral, 



i\bbe and iris, double nosepiece, 2/3 



and 1/6 



Beck Small "London," spiral, Abbe 



and iris, double n^isc-piece, 2/3 and 1/6 6 10 

 iwift " Discovery," eyepiece, 2/3, 



1/6, double nosepiece . . . . . . 5150 



Baker Student, eyepiece, A and D 



Zeiss objectives, double nosepiece 5 'O O 



Bausch & Lomb Student, i eyepiece, 



double nosepiece, 2/3 and 1/6.. .. 500 



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

 leading makers), Eyepieces, Double and Triple Nose- 

 pieces, Condensers, Lamps, Spectroscopes, Microtomes, 



Caljinets, etc. 



PRISM BINOCULARS 



ROSS. ZEISS, 

 GOERZ. etc., 



FOR SALE 



AND 

 WANTED. 



6 IS 



338 HIGH HOLBORN 



(dlipoM-.. (,r,^^■ Inn K.,.-,d), 



LONDON. 



MICROSCOPY. 



SPECIALLY ATTRACTIVE SLIDES 

 FOR POPULAR EXHIBITION CA' STUDY. 

 Zoology. Marine and Freshwater.— 



Unique preparations, ivitnoitr /•7-fssu?-t\ in then- natural 

 form and beauty for Dark Ground (or transparent), 

 Zoophyies,' AUditSiS, Polyzoa, with their glorious array 

 of tentacles; Holothurians with wheel plates, etc ; a 

 series of the curious Salpir and other Tunicatcs ; young 

 Cc/^/^'.y developing in their eggs ; the celebrated Lance- 

 let ; sX^o the Radiolarian SpluFrozoum^ the " Volvox of 

 the sea," etc., etc. 



Insects and Pants* — 'Lzxv^t.o^ Plumed G?iat 

 (also for polariscope). Superb tongues of the rare 

 Sylvan IVasp and Hornet, also piercing organs of the 

 Gadjly. etc., etc. 



Special Cements, Forceps, Scissors, etc., etc., for 

 Mounting and Dissecting. 



SECOND-HAND 



INSTRUMENTS, 



OBJECTIVES, &c. 



NEW LIST 



NOW READY. 



Post free on request. 



To Beginners. — Kxpert advice freely given 

 on selection of suitalile equipment; much time and 

 needless e.xpcnse can theieby be saved. Write or call. 



UfAMTpn Microscopes, Objectives, etc., or whole 

 """"-"' Outfits purchased for Cash. 



HXCHANGES MADE. 



CLARKE & PAGE, 



23, Thavies Inn, Holborn Circus, LONDON. 



LIVING SPECIMENS 



FOR THE 



MICROSCOPE. 



Volvox globator, UesEuid^, Diatoms, Spirogyra, 

 Amceba. Actinophrys. Spongilla, Vorticella, Stentor, 

 Hydra Cordylopohra, Stephanoceros. Melicerta. 

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

 with printed drawing, post free. Thomas Bolton, 

 Naturalist, 25, Balsall Heath Road, Birmingham. 



MINERALOGY AND 

 GEOLOGY. 



JAMES R. GREGORY & Co., 



Mineralogists. &c.. 



Are in ;-. HL'tter positir.n ib.ni ever fi:-]- supplying 



Collections of Minerals, Fossils & Rocks, 



.\s they lia\e recnilly made Lar,:;c purchases of 



mat'_-ri.d. 



LISTS AS USU.AL. 



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



Te^lephone : Western 2S41. 

 Telegrams : " Meteorites, London." 



SECOND-HAND DEPARTMENT. 



Microscopes, Telescopes, Spectroscopes, 

 Binoculars, Surveying Instruments, &c., 



BY THE BEST MAKERS AT MODERATE PRICES. 



Lists sent post tree on request. 



Scientific Instruments Bought, Exchanged and Sold 

 on Ccnunission. 



JOHN BROWNING, 



146 STRAND, and 72 New Oxford St., 



LONDON. 



Telegrams ; 

 ■AUKS." LONDON'. 

 E S T A B L I 



Telephone 

 S24 GERRARD. 



Stevens' Auction Rooms, 



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



t-,\cry Frii>av al Vl.'My Sales aie held at the 

 Rooms of iMlCKOSCOI'ES AND SLIDES, TELESCOPES, 



Surveying Instruments, Electrical and Scien. 



TiFic Api'aratus, 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 all Particulars Post Free. 



Valuations for Probate or Transfer, and Sales con- 



ducted in any part ol the Country. 



FOR ALL KINDS OF EDUCATIONAL 



Mineral Material, 



COMMON ORES, and SELECT CRYSTALLIZED 

 SPECIMENS, at ALL PRICES. 



G. H. 



I)c,,lcrs HI 



RICHARDS & Co., 



d! ki 



d> nf Bnti'ih and Foreign Mineral 



Spi.-cinii-ns. 



I'RlCn LISTS l-Rl'E. 



48 Sydaey Street, Fulham Road, South Kensington. 



London. S.W. 



F. WIGGINS & SONS, 



102, 103,104, Minopies. LONDON, E. 



Contractors to H.M. 

 Government 



LAMPS, 



STOVES. 



VENTILATORS, 



ELECTRICAL WORK 



Ar.D ALL PURPOSES. 



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



Printer of 

 ' Knouiedse." 



JOHN KING, 



Oxbridge, Southall, and Ealing, 



Ts favourably equipped for the PRINTING of 

 ■'■ Scientitic Books, Brochures, Catalogues, &c., and 

 will be pleased to submit estimates. 



Aildress all ComiiiunicatJons to 



213, IXBRIDGE ROAD, EALING, LONDON, W. 



■Plione: 1144 Ealuni. 



OUR INFORMATION BUREAU 



w.ll be found to be ni grent use lo boreign aud Coloniai leaders. OlteDtimes 

 information is desired which is unobtainable locaUy and :n such cases, whether tbt. 

 information is of a Literary, Scientific, Trade, or other character, we undertake, for 

 a small fee, to supply the information desired, if at all obtainable : and in order to 

 introduce our Bureau to the notice of the readers of Knou-ledge we will, for a limited 

 period supply such information at the rate of 6d. per enquiry. Stamps (Foreign or 

 British) will be accepted inpayment of the Enquiry Fee, and replies will be forwarded 

 by the earUest possible mail. We also act as Buymg Agents for readers resident in 

 the provinces or abrn;id. Full particulars sent gratis. 



E. GEORGE & SONS, 23 Jacob Street, London. S.E., England. 



Binding Cases for Knowledge Volume, 1914. 



IN BLUE CLOTH, WITH GILT DESIGN AND LETTERING. 

 7,s. <JJ. net ccic/i ; hy Post, 2s. 



I\N0WLED(;E office. Avenue Chambers, Bloomsbtiry Square, London, W.C. 



