KNOWLEDGE. 



November, 1910. 



CIVIL SERVICE COMMISSION. 



FORTHCOMING EXAMINATION. 



CARTOGRAPHERS in the HYDROGRAPHIC 



DEPARTMENT ol the ADMIRALTY (17-25) 



10th November. 



The date specified i-^ the latest at which applications 

 can be received. They must Lie made on forms to be 

 ubtained, with particulars, from the Secretary, Civil 

 Service Coniniission, Burlington Gardens, London, W. 



BOOKS! 



!'M.)ks oil Scienlittc, Technical, 

 I'cUic.Ttional. iMeilic.Tl, .tII olher 

 -ubjtfcls. and fui .ill ^:^.^llls. 



SECOND HAND AT HALF PRICES! 

 New, at 25 Discount. 



CATALOGUE'^ FlvEK. Sl.Tte wants. tlook-i sent on 



appr.jval. 



BOOKS BOrCHT—BESJ' FK/CES G/I'EX. 



W. & G. FOVLE, 135, Charing Cross Road, 

 London, W.C. 



SECOND-HAND TELESCOPES. 



31-in. Zeiss ApocIiiuni.,ii<. ,..n T.-ililt 



Standi, Piiidcr, l'>ectiiiL; l^j-epie(_=. i 



Astro. Eyepieces, 'I'ravelling Case. 



Cost o\er ^40. A.s new . , . . £28 10 o 



4-in. Wrayt 1 I^ay and 2 Astro. Eye- 

 pieces, Finder, .Altaz. Stand .. . 27 10 o 

 -^-in. Hug'hes, on Equatorial {nn circles). 



Finder, i Day and 2 Astro, Eyepieces 9 1 c; o 

 3-in. Aitchison, Vertical Rack, Finder, 



I Day and i Astro. Eyepiece, in case. 



complete . . . . 7 00 



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



Finder 6 00 



3-in. Student's do. do. 4 15 o 



6^-in. Browning Equatorial Reflector. 27 10 o 

 6i-in. Calver Alia/iinuih do . . 20 00 



SECOND-HAND MICROSCOPES. 



Beck Bactcriolu-lL.d £13 15 o 



Leitz do. 13150 



Watson do Edinburgh H model. 



complete . . 1600 



Beck Binocular 7 IS o 



Swift "Discovery " S 10 o 

 Bausch & Lomb Student's, 1 and ,' 

 Objectives, i Eyepiece Double 



Nosepiece . . . . 5 O O 



Beck Dissecting:. 4 powers 2 e; n 



Als>. A..ct-v,,i,,-s, (.-.liini-as, .umI rH.iri ts I.:\t '■..^, 



GLARKSON'S SECOND-HAND OPTICAL MART, 



338, HIGH HOLBORN, LONDON. 



(0[ipr,sitr t ir.ii, \ Itiri Ri.ad ) 



To improve your Telescope, use 



STEINHEIL'S 



ASTRONOMICAL EYEPIECES. 



In Stock, at Steinheil's list prices. 



Steinheil's Improved Huyghenian ,. Kl - each. 



do. .\chroniatic, of great 



brilliancy ' .. .. '21 - ,, 



do. Monocentric~ ., 21 - ,, 



STEINHEIL'S HIGH. CLASS ASTRONOMICAL OBJECT 

 GLASSES AM) T(H HIST TELESCOPES. 



A. CLARKSON & CO., 



338, HIGH HOLBORN, LONDON. 



((">pp. .sit..- I ;r.<\-\ hu, Rixul. I 



SECOND-HAND 



PRISM 

 FIELD GLASSES. 



s« iii l.i 

 b" £4 l.i 



CLARKSON'S, 



London. 



The Second-hand Oplir:il Mart, opposite ( Iray's Inn Rd. 



To P rospector s, &c. 



A Malicgaiiy Case- fur ali<i\c. cuTisisLmg i]| 

 Dichioisci.pe. Specific Gnuily Rule, Scintilla- 

 scope, 3 Ilarriiies-^ Hniiits, cS:c. . with iiirection> 

 for u<^e. Price 52/6. 



JAMES R. GREGORY & Co., 



Mineralogists, 



139, Fulham Road, South Kensington, 



Tt'(€f>lu»!,,2S4iW,^t,>>,. LONDON. S.W 



Telegraphic Address. "Meteorites, London." 



TUITION BY 

 CORRESPONDENCE 



Fur iMATRlCLiLATlON, B.A., B.Sc, an.l 

 other UMVKRSITY and PROFESSIONAL 

 EXAMINATIONS, an.l for INDEPENDENT 

 STUDY. 



Tut" ST.M- 1-- consists of Graduates of Oxford, 

 Cambridiie, J^ondoii, Dublin, and Royal Universities. 

 Address~yix. J. Charleston, B.A., HurIin;:;ton 



Correspondence Colle'j;e, Rirkbeck Bank Chambers, 

 T l..h, W.Q. 



MICROSCOPY. 



New and interestini: OBJECTS prepared 

 NATURALLY, i.e.. WITHOUT PRESSURE 



for dark (ground illumination. 



Fresh Watcrand Marine Slides.— /'tj/i'ctjn, Hydi-ozoa. 



extended as in li'e. beautiful mounts of Medusa , 

 Mollusea^ »5rV.. Phyilirr/ioe with entire anatomy vi-- 

 ibie. Fish parasites, Jltikcs, ^r'c. To those who ha\t 

 not seen the above ihey are a revelation of the beauty 

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



Insect Parts. — Head oi Sand Wasp with fine mouth 

 organs, entire Spiny Plant Bug from Ceylon ; also the 

 rare Wild Bee-pirasite Sty tops, young Trap-door 

 spider, &r=c.. &'e. 



Our li-^ts contain liesides the above, Geological, 

 Bo tan it a/. Platoiiis. 6-^f., ^c. 



SECOND-HAND. 



Microscopes, &C.— Present stock includes instiunient- 

 b\- Watson. A'oss, Zeiss, Filllscher, &rc. 



Ohjectives. -A large number in slock from 3-in. to 

 3^.-th. by leading makers. 



Accessories.— Eyepieces, Polariscopes, Sclenite 

 stages. S.S. reflectois. Condensers, Spot lenses, Nose- 

 pieces and a fine large Microtome. 



Ftili lists 0/ abiri'e, post free. 



U/AMTpn Microscopes and Accessories, of all 

 ifMUll-l/. \Cxns\s, purchased or exchanged. 



CLARKE & PAGE, 



Please Note New Address : 



23, Thavies Inn, Holborn Circus, 



LONDON. 



ASTRONOMICAL TELESCOPES. 



:;-iii. Table Stand u ith ■.; e\-c.piei_es i-I 10 



a-Mi. Garden 5tand with 3 eye-piece-> .. 8 10 



3^-in. Garden Stand with 3 eye-pieces .. 12 10 



4-in. Garden 5tand with 4 eye-piercs . 20 I) 



SECOND - HAND LANTERNS. 



Oil. Limelight. Electric. 



SECOND-HAND LANTERN SLIDES. 



By all the Leading Makers. 

 Also keiriilators. Jets, Lenses, *S;c. 



SECOND-HAND MICROSCOPES. 



WaisMii s Emnl^nrgh .-stuueia. CL.niplet.j £10 1) (I 



}!eck's Large London, complete ... .S 10 



Swift's Discovery, complete ,, .. .t l,i 



Walsi.n's Slandaul, :„uinplvte .. ,S |() 

 Lists on appruatiio:. 



BROADHURST, CLARKSON & CO., 

 63, Farringdon Road, London, E.G. 



I al.- ;:n N.ai- :<. r.aillfl;', lluil.Jih--. 



MlNERALOGICAL 



Specimens. 



ALL KINDS * PRICES EOK STl DENTS « TEACHERS. 



ROUGH 



PREC IOUS STO NES. 



LiUs h;Y ln„„ 



G. H. RICHARDS & Co., MiNERAuiuisTSaJc. 



.s7(i^-i' A>,' , ;j, Meauchamp Place, 



Hrompton Road, London, S.W. 



Collections or Single Specimens of 



CHOICE MINERALS. 



FOSSILS and ROCKS. 



.Ml kinds of Caitinets, Glass-capped Boxes. Card 

 Trays, Hammers. Hlo\\pipe Cases, ^c. , tS:c. 



k< II K SICCTK iNS, 9d. each. 

 4.000 CHOICE MICROSCOPICAL OB.IECTS, in all 



departments nt Nature, 6d. each. 



DllCCn I D OUAIAI 11- John St.. Theobalds 

 KUOOLLL & OnAW, Road, London. W.C. 



Cxliihgucs fix,. 



Telegrams : 

 ■.^UKS," LONDON" 



E 



Telephone ; 

 824 GERRARD 



TABLISHED 1 760. 



Stevens' Auction Rooms, 



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



K>t.y I-"Kn..*\ al Vl.VM, ,s.,lc, .iic Ijcid at liie 

 KooniS of iMTCkOSCOPES AND SlIUES, TblESCOPES, 



Surveying Instruments, Electrical and Scien- 



1 iFic Api'aratl s, Camer.as and Lenses, Lanterns 



AND .Slides, CiNEMATOGRArHS and Films, in great 



variety, Lathes and Tools, Etc. 



Goods may be sent for inclusion in early Sales. 



Settlements matie one week after disposal. 



CatnlOj^ufs and all Particiihjis Pi'st /•'<,•,■. 



Valuations fur Probate or Transfer, and Sales con- 

 ducted in any part of the Country. 



^^^piKvENsa 



The Whole 

 Star Sphere. 



l:> W. I'h^K", K.K.A.S. 

 ,^ Charts & i,o2o Illustra- 

 iL.msof Double Stars. Most 

 useful fur reference and 

 I linking Notes, marking 



Tracks of Comets, etc. 



i. ^ ^ntains Catalogues op 



Pouble. Variable, and 



'oloured Staf-s, Nebul(F, etc. 



A'c:^' J\i\i,iv. 



Pro<pec 



applnution. 



5/- NEW STAR ATLAS 



net. and Telescopic Handbook. 



i6 Charts, rovctin^ ihc St.ir splicii-, s)i,,uiti- nearly all 

 olijects in— (positions for 1920). 



WEBB'S CELESTL^L OBJECTS. 



SMYTH'S CELESTL'^L CYCLE. 

 [-•repaied with greatest care by A. P. Norton, B.A. 



GALL & INGLIS, 31, Henrietta St., London, W.C. 



THE SCIENTIFIC APPLIANCE 

 MANUFACTURING CO. 



l-'-r everylhinq ELKCTRICAL, GALVANIC, 

 MAGNETIC, OPTICAL and SCIENTIFIC. 



\\"iies, Ebonite, Lamps, Terminals, Coils, Bells, 



Castings. Accumulators from 3s. 6d. 



AVtC 00 page Electi'ic Catalogue /rec. 



X-Ray Coils, Static ISIachines, E.vperiniental and 



Inventors' Work. 

 Siemens' celebrated Obach and Hellesen Diy Cells 



and many ciiher batteries froiri (jii. 

 Model Aeroplane Materials. 



Wireless Telegraphic Materials. 

 PRISMS. LENSES, TELESCOPE PARTS, 



OPTICAL MATERIALS. List free. 

 I'lactical Mccliafiic^ and Electricians. Large Work- 

 shops. Repairs on the premises. 

 PRO-MPT! CHEAP! RELIABLE ! 

 HENRY J. DALE !ias h.ul v.ist e.Nperience ; 



v\ 1 itc Us — 



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



F. WIGGINS & SONS, 



102, 103, 104, Minories, LONDON. E 



Contractors to H.M 

 Government. 



LAfVIPS. 



STOVES. 



VENTILATORS. 



ELECTRICAL WORK 



AND ALL PURPOSES. 



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



ADVERTISEMENT RATES. 



i -. 'I. 

 Whole Page - - - - 6 6 O 



Half Page 350 



Quarter Page- - - - 1 15 O 

 One-Eighth Page - - - O 18 6 

 One-Sixteenth Page - - O 10 O 

 Per inch, Narrow Column O 7 O 

 Half ,. ., „ O 4 O 



I lisi .Hinls for Series of Insertions and Rales for Special 



I'nsitions, when \'acant. nn apjilicalion to 

 Thf Ai)\ ertishmi- n r M,\n\,.ek, 



KNOWLEDGE OFFICE, 



42, BLOOMSBURV SQUARE. LOSDON, W.C. 



