KNOWLEDGE. 



December, 1910. 



T-O PARENTS and GUARniA\5 



* established firm of Lon<. 

 Scienlific Instrument Manufacti:; . : 

 take a well-educated Youth as PLHIL: 

 partly returned as salary. — Address " B." 

 "Knowledge" Office. 



premium 



HOX 12. 



WANTED. 



DALTON'S MICRO. SLIDES 



of arriiiii'cd liutttril) Scales, Ac. 

 C. BAKER, 244. High Holborn. London. 



SECOND-HAND DEPARTMENT. 



Microscopes, Telescopes, Spectroscopes, 



Binoculars, Surveying Instruments, Sic, 



BY THE BEST MAKER S AT M ODERATE PRICES. 



JOHN BROWNING. 146, Strand, LONDON. W.C. 

 SECOND-HAND TELESCOPES. 



4A-in. Grubb, Finder. Altaz. Mami 



1 Day. 2 Astros. .. £30 O o 

 3;-in., 1 I'ay. 2 .Astro., Finder, on Alt.i/. 



Stand. Zeiss O.Q. - - 32 10 o 



3i-in. Franks Manchester, i l>.'i\ , 



2 Astrus. , un T;dl Stand -. '3 '3 *> 

 4-in. Wray, i Day and 2 Abtro. Eye- 

 pieces, Finder, Altaz. Stand .. 27 lO O 



3-in. Hughes, on Equatorial (no circles), 



Finder, 1 Day and 2 Astro. Eyepieces 9 150 

 3-in. Aitchison, Vertical Rack, Finder, 



I Day and 1 Astro. Eyepiece, in case,' 



complete .. .. 700 



3-in., I Day and 1 Astro. Eyepiece. 



Finder and Garden Stand 7 00 



3-in. Student's do. do. 4150 



6^-in. Calver Altazimuth do . . 20 00 



Also Accessories. 



SECOND-HAND MICROSCOPES, 



Beck R.irteriM|,,-i, .,| 



Zeiss, Stand I e. Large Mech. Sr.igi- 



Zeiss Projection Outfit, for use with 



above, complete . . 

 Swift Eacteriologial Outfit complete. 



7^ and Mech. Stage 

 Swift ' ' Discovery " 

 Bausch & Lomb Student's, ^ and ,'. 



Objectives, i Eyepiece, Double 



Nosepiece 

 Beck Dissecting, 4 powers 

 Binocular Microscopesby Ross, Watson 



and Beck, fn.im 



I.S 



l-t 



5 



o o 

 10 o 



o o 

 5 o 



7150 



Also AcctsM.iics. C.iiiiiiets. .'hm! (")hi..-. t, /_/, 



GLARKSON'S SECOND-HAND OPTICAL MART, 



33S, niOH HOLBORN. LOSDON. 



(( IpixiMte i;r,iy\ Inn K".,il I 



To improve your Telescope, use 



STEINHEIL'S 



ASTRONOMICAL EYEPIECES. 



In Stock, at Steinheil's list prices. 



StcinheiKs Improved Huyghenian .. Ill, -each, 

 dj. Achromatic, of great 



brilliancy . . . . 21,'- ,, 



do. Monocentric . . 21 ■ ., 



STEINHEIL'S HIGH-CLASS ASTIIONOMICAL OBJECT 

 CLASSES AND TOLRIST TELESCOPES. 



A. CLARKSON & CO., 



338. HIGH HOLBORN, LONDON. 



(()j)[M>^i^c i;ray\s Inr. Road.) 



SECOND-HAND 

 PRISM 



FIELD GLASSES. 



i;"-.s s< f.i 15 



Zkiss nx £4 15 

 V.oiiRj ll« £4 15 



GLARKSON'S, 



s, //;;.'A lloli^^ru, 

 London. 

 The Second-hand Optical Mart, opposite (Iray's Inn Rd. 



Coal Plant Sections. 



Finest Series in London at 

 Reasonable Prices. 



JAMES R. GREGORY & Co., 



Mineralogists, &c.. 



139, Fulham Road, South Kensington, 



^ Phone, 3S41 Western. ® ^ 



Telegrams, '''' Meteorites, London" 



TUITION BY 

 CORRESPONDENCE 



lir MATRICULATION, B.i., B.Sc, ami 

 ilier UNIVKKSITY an 1 PROFESSIONAL 

 EXAMINATIONS, anil fur INDEPENDENT 

 STUDY. 



Thk Staff consists of Graduattrs of Oxford, 

 Cambridge, London. Dublin, and Royal Universities. 

 Address — Mr. J. Charleston, B.A., P.urlin^ton 



Cnrrcspi-MidenL-e College. P.irkbeck Bank Chambers. 



I.,>nd>>ti. W.C. 



MICROSCOPY. 



New and interestina; OBJECTS prepared 

 NATURALLY, i.e , WITHOUT PRESSURE 



fur dark y:round illumination. 



Fresh Water and Marine Slides.— /'c/i'::('/r, Jiydro:.oii. 

 extended as in life, beautiful mnunts of Meihisac, 

 MolluS'-a, £^c.. Phyllirrhoc with entire anatomy vis- 

 ible, Fish pa7-asitcs. Jhikcs, &^c. To those who have 

 not seen the above they are a revelation of the beauty 

 to be found in the fauna of our own and tropical seas. 



Insect Parts. — Head of Sand ll'asp with line mouth 

 inu.^r s. entire Spinv Fhtni Bug from Ceylon ; also the 

 rare \\"ild Bee-pirasite Styhps, young Trap-door 

 Spider, (S-V., (St-V. 



Our lists contain besides the above, (ieo/ogica/. 

 Botanical^ Diatoms, &^c:., S^c. 



SECOND-HAND. 



Microscopes, &C. — Present stock includes instrument^ 

 I y Watson. Ross, Zeiss, I'tlUschcr, &'l. 



Objectives. —A large number in stock from 3-in. to 

 i',_,-tii, by leading makers. 



Accessories. — Eyepieces, Polariscopes, Sclenite 

 stages, S.S. reflectors, Condensers, Spot len.ses, Nose- 

 jiieces and a fine large Microtome. 



Full lists 0/ al'ozie, post free. 



lUAUTCn Microscopes and Accessories, of all 

 tlHUICU. ^j,„|,^ purcba-^ed .^r ex.-hnnt^ed. 



CLARKE & PAGE, 



Please Sote Sew Address: 



23, Thavies Inn, Holborn Circus, 



LONDON. 



ASTRONOMICAL TELESCOPES. 



.■i.iii. Table .^tand with ' tve-pieces £4 10 



S.iii. Garden Stand uilh 3 eye-pieces .. 8 10 



y'-in. Garden Stand u itli 3 eve-pieces , 12 10 



4:111. Garden Stand uiih 4 L-ve.pi.. es 20 



SECOND - HAND LANTERNS. 



Oil, Liinelifiht, Electric. 



SECOND-HAND LANTERN SLIDES. 



By all the Leading Makers. 

 AKso l^eiciilator.v, .let?, I.eii.-;e.-;, 



&c. 



SECOND-HAND MICROSCOPES. 



\Vats'>n's Ediiiburpjh Student, complete Xlfi 



I'eck's Large London, complete .. . S 10 



Swift's Discovery, complete .. 5 15 



Watson's Standard, complfte .. 5 10 

 Lists on application. 



BROADHURST, CLARKSON & CO., 

 63, Farrlngdon Road, London, E.G. 



I. .Tie 311 ye.irs is, l:arlleU\ l;uil<lih'.;s. 

 s;KI Ki"1' .^ I'HliHF sMAI 1 



Crystallized & Crystalline Mineral Specimens 



MICROSCOPIC SLIDES 

 AT 4d. EACH. 



/,7./,r -G. H. RICHARDS & Co., 



Dealers in all kinds of British & rnrei^n 

 Mineral Specimens. 



Sho-.v A'oiuji'i : 3, Beauchamp Place, 



Brompton Road, South Kensington, London, S.W. 



Collections or Single Specimens of 



CHOICE MINERALS. 



FOSSILS and ROCKS. 



All kinds uf Cabinets, (jjass-cappcd Boxes, Card 



'liays. Hammers, Blowpipe Cases, &c., &c. 



ROCK SECTIONS. 9d. each. 



4.000 CHOICE MICROSCOPICAL OBJECTS, in all 



departments nf Nature, 6d. each. 

 niioon I CUAUI 11. John St.. Theobalds 

 KUoOtLL & OHAW, Road. London. W.C. 



C,tt,l/0i;i<fS fra. 



Telegrams : 

 ALTRS," LONDON. 



Telephone : 

 li GERRAkD 



iTABLISHED 



Stevens' Auction Rooms, 



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



Kvery Fkidav at 1'2.3U, Sales are held at the 

 Rooms of MicuoscoFEB AND Slides, Telescopes, 

 Slrveying Instruments, Kleci rical and Scien- 

 tific Apparatus, 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 Pa}-ticutars Post F^ee. 



Valuations fnr Probate or Transfer, and Sales con- 

 ducted in an\ part nf ilic Cnuntn. 



^^The Whole 

 Star Sphere. 



Hy \V. Peck, K.K.A.S. 



■ Chart? & i,o2o lUustra- 



: 1. Ills of Double Stars. Most 



u-^eful for reference and 



making Notes, marking 



Tracks of Comets, etc. 



Ffntains Catalogues of 



T>oul>U% I'ariablc, and 



Coloured Stars, Nebuhp, etc. 



.\oxo Rtady. Trioe 5 - net. 



NORTON'S STAR ATLAS 



and Telescopic Handbook, 



Covering the whole Star sphere, by A. P. Norton, B. A. 

 This neiu and handy Atlas is the latest and most 

 complete of its kind. 

 I'i.r beginners and sienera! use, its handiness is 



1. iii.iri::,M.-, ^ - 



GALL & INGLIS, LONDON and EDINBURGH. 



THE SCIENTIFIC APPLIANCE 

 MANUFACTURING CO. 



F..r eVL.viliin- ELHCTKICAL, GALVANIC, 

 MAGNETIC, OPTICAL aud SCIENTIFIC. 



W'iics, Elionite, Lamps, Terminals, Coils, Bells, 



Castings. Accumulators from 3s. 6d. 



AVw 6o p^ge Electric Catalogue free. 



X-Ray Coils, Static Machines, E,\perimental and 



Li\eiitors' Work. 

 .Siemens' celebrated Obach and Hellesen Diy Cells 



and many oiber batteries from qd. 

 Model Aeroplane Materials. 



Wireless Telegraphic Materials. 

 PklSMS. LENSES. TELESCOPE PARTS, 



OPTICAL MATERIALS. List jree. 

 I'ractical Mechanics and Electricians. Large Work- 

 shops. Repairs on the premises. 

 PROMPT! CHEAP! RELIABLE! 

 HENRY J* DALE has had vast experience; 

 uiite US- 

 IS, NEW OXFORD STREET, LONDON, W.C. 



F. WIGGINS & SONS, 



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



Cuntractor.s to H.M. 

 Government. 



LAMPS. 



STOVES. 



VENTILATORS, 



ELECTRICAL WORK 



AND ALL PURPOSES. 



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



ADVERTISEMENT RATES. 



i I i 



Whole Page - - - - 6 6 O 



Half Page 3 5 O 



Quarter Page- - - -1150U, 



One-Eighth Page - - - O 1 8 6 , [^ 



One-Sixteenth Page - - O 1 O -^ 



Per Inch, Narrow Column O 7 O I 



Half ,, ,, .. O 4 O' 



ItlbLoLiiilb fur ^erici uf IiisL-rtioli^ .iiid Rates fur Special 



Positions, when Vacant, on appljcalion to 



The Advertisement Manager, 



KNOWLEDGE OFFICE, 



42, BLOOMSBURY SQUARE. LOSDOIS. W.C. 



