KNOWLEDGE. 



September, 1910. 



CIVIL SERVICE COMMISSION. 



FORTHCOMING EXAMINATION. 



ASSISTANT in the ROYAL OB5KRVATORV. 

 EDINBURGH (21-25), 20th OCTOBER. 



The date specilied is tlie latest at which applications 

 can be received. They imlst lie made on forms tn be 

 obtained, with particulars, from the Skcrf.tary, Ci\il 

 Ser\ice Coiiiinissiuii. lUirhiiL^hin (hardens, I,ond.>n, \\'. 



WANTED. Barton's Diffraction 

 Buttons, one or t\\o examples. 

 Please state price and design. "T. E. F..'' 

 "Kenmoie," Woodside Tails !;■ ml. Xnrth 

 Finchley. N. 



SECOND-HAND TELESCOPES. 



4-in. VVray, i LKi\ ..n,". .: Ami... i-.>.- 



pieces, Finder, Allaz. Stand .. £27 10 o 



i,-\n. Hug;hes, 011 Equatorial (no circles', 



tinder, i Day and 2 Astro, Kyepiecc* 1 5 *> 

 vin. Aitchison, Vertical Rack. Finder, 



I Day and i A.stro. Kyepiece, in case, 



complete .. ■■ •■ ■■ 7 00 



:;-in.. J Day and i Astro. Eyepiece, and 



Finder 6 00 



s-in. Student' .«i da do. 4150 



b^-in. Browning Eqnaiorial Keflector , 27 10 o 



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



A!^.- ■X-^.-.-.-.-.vi-s 



SECOND-HAND MICROSCOPES. 



Beck liacteriological £13 15 O 



Leitz do. 13 15 o 



Watson do. Edinburgh H model, 



complete . . . . . 1600 



Beck Binocular 7 'SO 



Swift "Discovery" 5100 



Bausch & Lomb Student's, .7 and ,'. 

 Objectives. i Ryupiece, Double 

 Nosepiece . . . - . . . 5 ^ ^ 



Leitz I>issectiMg, i po\\<Ms 



Also Accessories, Cahillel^. .md ("Hii._i.ts. List /nr 



CLARKSON'S SECOND-HAND OPTICAL MART, 



JJS. HIGH HOLBOR.\. LONDON. 



((l,,li..MIc (...,n\ Inn K-.ul ) 



To impro^•e j our Telescope, use 



STEINHEIL'S 



ASTRONOMICAL EYEPIECES. 



In Stock, at SteinheiL's list prices. 



Steiiiheil's Improved Hiiygheniaii .. 10 - each, 

 do. Achromatic, of uLcal 



brilliancy' . . '21 - ., 



do. Moirocentric ".^1 - ., 



STEINHEIL'S HIGH-CLASS ASTRONOMICAL 0B.1ECT 

 GLASSES AM) TOIRIST TELESCOPES. 



A. CLARKSON & CO., 



338, HIGH HOLBORN. LONDON. 



(I^)|.|ii.-i:'/ r,i..\'s 1,11. K.-,h1, 1 



SECOND-HAND 



PRISM 

 FIELD GLASSES. 



,s ,s« £3 15 

 ~s s« £4 15 



K, :i« £4 15 



CLARKSON'S, 



3:j^, /h'^/i Holl'Pru, 

 London. 

 ']>prisite ("tray's Inn Rtl. 



BOTANICAL MICROSCOPIC 



SLIDES FOR STUDENTS, 



Including Four Series, - Slilit;^ lu c.ilIi. iVitt-- .i{ii i -.. 

 per series ; illustrating; Aii^jsis, Leucoplasts, Thyloses. 

 Root, Stem, and Flower Development, Anomalous 

 Stems. Embryo-sac Structure. Pollen Tubes. Alg^e, 

 Fungi, Anthoceros, Pilularia, Marsilia Isietes, Sela- 

 ginella, Pinus, etc. Catalogue i\'^: FriW 



A. PENI5TON. 5, Montpelier Terrace. Leeds. 



Collection of Fluorspars. 



JAMES R. GREGORY & Co. 



I Live acqaiicti a very Fine Collection of 

 Fluorspars from the North nf England, 

 principally from Co Diuiiani, and ihcy may 

 lie seen at their large premises, 



139, Fulham Road, London, 5.W. 



(Near South Kensington Station). 

 Telephone., 2S41 Western. 

 Telegraphic Address, ^'Meteorites." 



TUITION BY 

 CORRESPONDENCE 



Ir tMATRICliLATION, B.A., B.Sc, an.l 

 other INIVKKSITY and PROFESSIONAL 

 EXAMINATIONS, and for INDBPENDUNT 

 STUDY. 



The Stakf consists of Graduates of Oxford, 

 Cambridge, London, Dublin, and Royal Universities. 



Address— "Mr. ]. Charleston, P.. A.. Hurlinuton 

 Correspondence Collecre, Eirkheck Bank Chamber.-. 

 LondoiK W.C. 



THH .MARrJNCi HNDOWED SCHOOL, 

 Stroud (OIos. ). 



.\ i'nih. !■ ■■ ^^. '\ s. b,.,-! (iSZu). Mathe- 

 matics, and Natural Science a 



strong feature, [h'l-'-ent siu-cessLi nuhi.i,- 



3 Fnst Ciiis.sis Tripos, '■^'i London .Matrix, 17 

 Inter. SeL.ete.). Splendid modern Buildings on 

 gravel soil. Fine l.,aboTatories and Gymnasium. 

 Ueautifnl country. Large playing fields. Apply 

 to the Headmaster. 



MICROSCOPY. 



New iind intertstinir OBJECTS preriired 

 NATURALLY, ie , WITHOUT PRESSURE 



for dark ground illumination. 



Fresh Water and .Marine Slides.— /V/j'^t^a. IJydrozoa. 

 trvt<_-(iiif^il .i-s III lite, ben II tiki I mounts of Me-iuso\ 

 Molhtsi'd, iSrV., I^JiylliJ'ihoe with entire anatomy \ l^- 

 ihle. Fish parasites, Jlvkes, <5-V. To those who ha\.. 

 not seen the above they are a re\elation of the beauty 

 to be found iii the fauna of our own and tropica! seas. 



Insect Parts. — Head oi .Sand U'as/> with fine mouth 

 organs, entire S/inv Plant Bug from Ceylon ; also the 

 rare Wild Bee-pirasite Stylops, young Trap-dooi 

 .spider, &^e., &~\-. 



Our lists contain besides the ai.iove. Ceologicj/. 

 BotanittiL J^iatonis. ^~. .. l~. . 



SECOND-HAND. 



■Microscopes, &C. — Piesent stock includes instruments 

 1 \ ll'iitson, Boss, Zeiss. PilUscher, is^c. 



Objectives. — .\ large uumbei- in stock from 3-111. to 

 I'j-tli. by leading makers. . ^ 



Accessories.^Eyepieces, Pol ari scope -^j Selenite 

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

 pieces and a fine large Microtome. 



Ftill lists 0/ ahoz'c, post free. 



UfAUTCn Microscopes and Accessories, of all 

 ""*" * ^^' kind-H. purchased or exchanged. 



CLARKE & PAGE, 



Pivasc .\ote \ew Addrtss': 



23, Thavies Inn, Holborn Circus, 



LONDON. 



LIVING 



SPECIMENS 



FOR THE 



MICROSCOPE. 



\",.i\t>x -1..1 ..,!.. I, Ik-HMi.i-. lii.U.->ms, SpiM,^\i-.i 

 Anntba. .Actinuphrys. Spungilla, \'orticella. St en tor. 

 Hydra Cordylopohra, Stephanoceros, .Melicerta, 

 Poly/oa and other forms of Pond Life, is- per tube, 

 with piinted diauing. post free. ThomAs IjOLto\. 

 Natmalisi. .:^. KaUall He.ith Road. Biriningham. 



mluRO'OBJEGTS forli^ountin^. 



u 1 >i>iii'i\- St. lined llotaniral :^ections, 



iS Miscellaneous Specimens, 6 Insect Parts, 



Is. Id. per Series, with full instructions, p >st free. 



iW See Micro. Editor's remarks. Jan.., 'oq. 

 I'l.Htical Hints on Mounting, with specimen, 



6 stamps. 



R. G. MASON. 7<S. Foxbourne Road. 



L'pper rooting, London, Jr-.W. 



Prismatic Binoculars 

 Army Field Glasses 



by Zeiss, Ross, &c. 

 by Ross, Watson, 6cc. 



Telegrams : Telephone : 



AUKS," LONDON. S24 GPIRRAKD 



Established 1760. 



Stevens' Auction Rooms, 



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



Kvery Friday at 12.30, Sales are held at the 



Kooiiis of MlCkOSCOPES AND SlIUES, TBLESCOPES, 



Si'inEviNO Instruments, Ei-ect ricai, and Scien- 



iiFic Aptarati s, Cameras and Lensks. Lanterns 



AND Slidi-:s, Cinematographs and Films, in great 



variety, Lathes AND TooLS, Etc. 



Goods may be sent for inclusion in early Sales. 

 Settlements made one week after disposal. 



ASTRONOMICAL TELESCOPES. 



O'Wx. Table Stand wiiii "2 e\e-picLcs 

 S-in. Garden .Stand wiib 3 eye-pieces . 

 ;i,'»-iii. Garden Stand with 3 eye-pieces . 

 4-ni. Garden .Stand with 4 eye-pieces . 



Comet Eye-pieces 



/. /f.' ("/ application. 



Tourist, Deerstalker, Miniature Rifle Telescopes. 



Spt\i<ii List to suit all rcqitironcnts. 



Telescopes, Microscopes and Scientific Insirttments 



Bon,^/!t. Sold or F-Vc/iaiiiicd. 



BROADHURST, CLARKSON & Co7^ 



63, Farringdon Road, London, E.G. 



L.Uc liU ji., lis lib, llarllett's Buildiii-s. 



Catalogues and all Particulars Post Free. 

 Valuations for Probate or Transfer, and Sales con- 

 ducted in an> part of the Countr\. 



The Whole 

 5tar .Sphere. 



W. PiiCK, F.R.A.S 



its & ],o2o lUustra 



Double Stars. Most 



for reference and 



; Notes, marking 



of Comets, etc. 



tins Catalogues of 



I 'arialdc, and 



I .-■/oi/ri.d Sfar.'.. y.l'uhr.ctc. 



GALL &. INGLIS. 31. Henrietta Street, 

 London, W.C. and Edinburgh. 



BOOKS! 



Books on Scientific. Technical, 

 Educational, Medical, all other 



su'-jects, and f.-.i all K,\ams. 



SECOND HAND AT HALF PRICES! 

 New, at 25 ', Discount. 



Catalogues Fkek. State w.uits. I'.noks sent on 



appro\al. 



BOOKS BOl'fMlT-BFST TBICFS CU'EX. 



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



i^ondon, W.C 



THE SCIENTIFIC APPLIANCE 

 MANUFACTURING CO. 



For .^LiMlmu llkctrical. galvamc, 

 MAGNETIC, OPTICAL .md 5C1LNTIFIC, 



Wires, Ebonite. Lamps, Terininals. Cods, Bells, 



Castings. Accumulators fiom 3s. 6d. 



Ne'a< 60 page Electric Catalogue free. 



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



Inventors' Work. 

 .Siemens' celebrated Obach and Hellesen Dry Cells 



and many other batteries from q<.1. 

 Model Aeroplane Materials. 



Wireless Telegraphic Materials. 

 PR15M.^. LENSES, TELESCOPE PART5, 



OPTICAL MATERIALS. List jrec. 

 Practical Mechanics and Electricians. Large Work- 

 shops. Repairs on the premises. 

 PROMPT! CHEAP! RELIABLE I 

 HENRY J. DALE has had vast experience; 

 \viilc us — 



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



MiNERALOGICAL 



Specimens. 



ALL KINDS 4 I'RICLS IIIU STl DLXTS ,V TLICHLKS. 



ROUGH 



PRECIOUS STONES. 



G. H. RICHARDS & Co., mim kalogists «c. 



Sho-LO Kooins—'i, Heauchamp Place, 



Brompton Road. London. S.W. 



F. WIGGINS & SONS, 



102, 103, 104, Minonies, LONDON. E 



Contractor.s to H..M 

 Government. 



FOR 



LAMPS. 



STOVES. 



VENTILATORS. 



ELECTRICAL WORK 



AND ALL PURPOSES. 



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



