KNOWLEDGE. 



March, 1915. 



CLARKSON'S 



SECOND HAND 



OPTICAL MART. 



TELESCOPES. 



.>_■.;,. \\'ray,niuunl- 

 ed uii massive oak 

 lath stand with 

 stretchers, hori- 

 zontal and vertica! 

 movements by 

 Hooke's joint, 

 slow motions. large 

 finder, 4 astro, and 

 r day eyepieces . . £40 

 4-in..fii!l,Negretti 

 & Zambraalta/-. 

 finder, i day, :; 

 a>tros.. in case .. .. .. ..25 



j.^-in. Baker, on ahaz. stand, horizontal 

 and vertical motions, finder, day ami 

 2 astros. . . .. .. ., ..171 



3i.in. Dollond, on ahaz. stand, finder, d.^y 



and 2 astros. ,, ...121 



3-in. Steward, on altaz. with equatorial 



(undivided circles), i day, 2 astros. . . ill 

 3-in. Wood, 1 astro, and 1 da\- eyt-pieces 



Many others. Also P^lyepit 



s. Diagonals, eti- 



MICROSCOPES. 



^ 



14 14 



Watson " Eidinburgh 



Student's *' iiino.u- 



lar, 3 eyepieces. 2-in., 



i-in., 5-in., polari- 



scope. and case 17170 



Watson " E:dinbur^h 



H,** - ■;. 1 T'. I I 2 (>. i, , 



2 eyepiei, e^, triple S^i'D^/^ 

 nosepiece, and Abl>e 15 15 o j^'tff- 



Beck Large "London," 



3 eyepieces. 2,:;, i/6. 

 and 1/14 oil immersion 

 objectives, triple nosepiece. spiral Abbe 

 and iris, mechanical stage, as new 



Baker "D.P.H." Stand, triple nosepiece. 



Ablie, ami cvse 

 Watson *' Fram," eyepiece, spiral, 



Abbe and iris, double nosepiece. 2/3 



and 1/6 



LeitZ lib, eyepiece. 3 and 7 objectives. 



double nosepiece. spiral Abbe and iris 

 Beck Small "London." spiral. Abbe 



and iris, <louble nosepiece, 2 3 and t/6 

 Swift "Discovery,** eyepiece, 2/3, 



ID, ilouMe nosepiece .. .. ". 



Bausch & Lomb Student, i eyepiece 



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

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

 leading makers). Eyepieces, Double and Triple Nose- 

 pieces, Condensers. Lamps, Spectroscopes, Microtomes, 



PRISM BINOCULARS 



BY 



ROSS. ZEISS. 

 GOERZ. etc.. 



FOR SALE 



AND 

 WANTED. 



338 HIGH HOLBORN 



(Opposite Cray's liin Ro.-uli, 



LONDON. 



5 IS 



s 



MICROSCOPY. 



SPECIALLY ATTRACTIVE SLIDES 

 FOR POPULAR EXHIBITION ^ STUDY. 

 Zoology, Marine and Freshwater.— 



Unique preparations, ivitHou: p7-e.%sn?-t\ in their natural 

 form and beauty for Dark Ground (or transparent;, 

 Zoophytes, MedusiE, Polyzoa, with their glorious array 

 of tentacles; Holoihuyians with wheel plates, etc. ; a 

 series of the curious Salpie and other Tunicates \ young 

 fjt»<^/(?j' developing in their eggs; the celebrated Lance- 

 iet ; also the Radiolarian Sphtprozouvt, the " Volvox of 

 the sea." etc.. etL. 



Insects and Parts. — \.'3,x\'2^oi Plumed Qptat 

 (also for polariscope). Superb tongues of the rare 

 Sylvan /frtj;/ and Hornet, also piercing organs of the 

 Gadjly. etc., etc. 



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

 Mounlins and Dissecting. 



SECOND-HAND 

 INSTRUMENTS, 

 OBJECTIVES, &c. 



NEW LIST 



.voir READY. 



Post free Oft request 



To Beginners.— Expert advice freely given 

 on helection of suitable equipment; much lime and 

 Me':dle>> expense can thereby he saved. Write or call. 



UfANTrn Microscopes, Objectives, etc., or whole 

 TtMlllfcU. Outfits purchased for Cash. 



i \CHANGES MAIjE. 



CLARKE & PAGE, 



23, Thavies Inn, Holborn Circus, LONDON. 



LIVING SPECIMENS 



FOR THE 



MICROSCOPE. 



Voivo\ globator, JJesniids, Diatoms, Spiro§yra. 

 Amoeba, 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. 

 N'aturalisl. 25, Balsall Heath Road. Birminshani. 



MICROSCOPIC SECTIONS 

 ROCKS & MINERALS CUT 



either from Stock or Clients' 

 owrn Materials. 



JAMES R. GREGORY & Co., 



Mineralogists, Sec, 



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



Telephone: Western *2S41. 



Telegtams: "Meteorites, Londij'i." 



SECOND-HAND DEPARTMENT. 



Microscopes. Telescopes, Spectroscopes, 

 Binoculars. Surveying Instruments, &c., 



BY THE BEST MAKERS AT MODERATE PRICES. 



Liits sent po-;t iree on request. 



Scienti/tc Instruments Bought, Exchanged ani Sold 

 on Commission. 



JOHN BROWNING, 



146 STRAND, and 72 New Oxford St.. 



LONDON. 



lelegrams ; 

 '.■\UKS," LONDON. 



Telephone 

 S24 GERRARD. 



Established 



Stevens' Auction Rooms, 



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



K\ery Friday at 12.30. Sale> .ire held at the 

 Rooms of MicKOSCopEs and Slides, Tf.i.escopes, 

 Surveying Instklments. Electrical and Scien- 

 tific APrARATi;s, Cameras and I. esses, Lanterns 

 AND Slides, Cfnematograihs and Films, in great 

 variety, Lathes and Tools, Etc. 



floods may be sent for inclusion in early Sales. 



Settlements made one week after disposal. 



Catalogues and all Particulars Post Free. 

 Valuations tnr Probate or Transfer, and Sates con- 

 ducted In an> part o( the Couiitr\. 



ALL KINDS OF BRITISH AND FORSIGN 



Mineral Specimens, 



COMMON MINERAL ORES, and 



CHOICE CRYSTALLIZED SPECIMENS at 



ALL PRICES oa view at 



RICHARDS' SHOW ROOMS, 



48 Sydney Street Fulham Road, South Keosingtoa. 

 Loadoo, S.W. 



PRlCh LlSl'S t^RE^. 



F. WIGGINS & SONS, 



102, 103, 104, Mmones, LONDON, E 



Contractors to H..M 

 Government 



rOR 



LAMPS. 



STOVES. 



VENTILATORS, 



ELECTRICAL WORK 



AND ALL PUhPOSES. 



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



Printer of 

 Knowle.lae.' 



JOHN KING, 



Uxbridge, Southal). and Ealing, 



I s favourably ei4uippcd fur ttie PRINTING of 

 ^ Scientitic Books, Brochures, Catalogues, &c., and 

 will he pleased to submit estimates. 



.■\iiiiress all Communications to 

 213. IXBRIDGE ROAD. EALING. LONDON, W. 



"Phone. 114^ Ealins- 



Binding Cases for Knowledge Volume, 1914. 



IN BLUE CLOTH, WITH GILT DESIGN AND LETTERING. 7s. .<W. net cucli : by /.ov^ i.v. 



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



A most fMCce/ttattle Gift at any time. 



KNOWLEDGE VOLUME FOR 1914 



C'j..l;in.ins 440 Pages ■>.;:. 425 IlluStpatiOnS, iiK,i,y :.eina Ktiil f..,c I,.,..,. 

 Bound in Blue Cloth, Gilt Design and Lettering, 15,- net. post free within the United Kingdoni. 



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



