May 4, 1905] 



NA TURE 



APRS, 



433 STRAND, LONDON. 



MANUFACTURER of Patented Induction Coils, other 

 Scientific Instruments and Engineering Appliances 

 to the Government Departments. 



JOINTLESS SECTION COILS, my system of 1868, to order, loin. Coil, 

 4000 ohms R, very thick discharge. Primary Coils for lo to 23a volts. 



COMMERCIAL SERIES OF COILS, as Fig , at about one-half of cata- 

 logue prices. 



of the follo« 



Coils 



Maker and 7>p 



POLYTECHNIC, =9 in- spark. 



SPOTTISWOODE, 44 in- spark. 



THE SOUTH KENSINGTON COIL, 48 in. spark. Special Coils for 



Wireless Telegraphy. 



NEW TRIPLE-POLE MERCURY BREAK, giving a stream-like effect 



when used with Apps' Patented Induction Coil (this can be fitted to 



any Induction Coil), £6 6s. 

 HOSPITAL X-RAY SETS, complete in every detail, from £25 each. 

 The Model Apparatus adopted for South Africa, with Batteries, small 



Steam Motor, &c. SETS OF X-RAY APPARATUS suitable for 



Field Hospitals, from £50. 

 HIGH FREQUENCY APPARATUS of my newest models. 

 PRICES per return post. 



MARCONI'S WIRELESS 

 TELEGRAPH COMPANY, 



Manufacturers of 



ELECTRICAL INSTRUMENTS 



of all kinds for 



LABORATORY .?S?. WORK, 



of the highest degree of efficiency 

 at moderate prices. 



ILLUSTRATED BRICE LIST I'OST 

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London Office : 18 FINCH LANE, E.C. 

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ALSO AT 



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Autotype Company 



74 NEW OXFORD STREET, LONDON, W.G. 



MONOCHROME COPIES by the 

 PERMANENT AUTOTYPE CARBON 

 PROCESS of PICTURES by OLD MASTERS 

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Numerous examples of w/orks by 

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The AUTOTYPE COMPANY'S Processes of Per- 

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 the Local Goveinnient Board, many of the Learned 

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Copies of Coins, Seals, Medals, MSS. , Drawings, 

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Inquiries are invited from those requiring B lok Illustra- 

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The Autotype Fine Art Gallery, 



74 NEW OXFORD STREET, LONDON, W.C. 

 OPEN FREE DAILY FROM 10 TO 6. 



MR. EDWARD ARNOLD'S NEW BOOKS. 



THE EVOLUTION THEORY. 



By AUGUST WEISMANN, 



Professor of Zoology in the University of Freiburg. 



TRAN.SLATED BY 



Professor J. ARTHUR THOMSON and MARGARET THOMSON. 



Two volumes, Royal Svo. With many Illmlrations. 32s.net. 



ASTRONOMICAL DISCOVERY 



By HERBERT HALL TURNER, D.Sc, FR.S., 



Savilian Profe^or of Astionomy In ill.; University of O.^ronl. 

 With Illustrations and Di, grams. Demy Svo. lOs. 6d.nel. 



THE CHEMICAL SYNTHESIS 

 OF VITAL PRODUCTS, 



And the Inter-Relations between Organic Compounds. 

 By R. MELDOLA, F.R.S., V.P.C.S., F.I.C., &c., 



Professor of Chemislry in the t ilyand Guilds of I,, ndon Technical Co'lege, 

 Finslury. Super Royal Svo. 21s.net. 



THE BECQUEREL RAYS 



AND THE PROPERTIES OF RADIUM. 



By the Hon. R. J. STRUTT, 



Fellow of Trinity ColleKe, Cambridce. Demv Sv.,. Wiih Diagrams. 

 8s. 6d. net. 



ENGLISH ESTATE FORESTRY 



By A. C. FORBES, 



Lecturer on Forestry at Armslron!; College, Newcastle, lately Forester 



on the Marquis of Bath's Longleat Ksiale. 



With Illustrations. Demy Svo. 1 2s. 6d. net 



London: EDWARD ARNOLD, 41 & 43 Maddox St., W. 



