VOLUME XXXVIII. NUMBER 559. 



New Series. Volume XII. Part 2. 



Entered at Stationers' Hall. Articles : 



FEBRUARY, 1915. 



FOLNDED BV RiCHARU A. PrOCTOR, ISSl. 



-Plainly Worded. Subjects : — Exactly Described. 



Registered for Canadian and 

 Newfoundland Magazine Postage. 



TRENCH HYPERSGOPE 



PERISCOPE. 



(Regd. No. 6J432U.) 



The "METRON" FOLDING MODEL, 



27-ln. long when open, closing to 27 ■ 7' xl-ln. 



Mirrors being of best patent plate the 



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A. In 3-pl}' Mahogany ... £1 5 O 



B. ,, Metal ... "... 1 10 O 



Eotii models painted waterproof Government grey. 

 Strong can\as case, with 



pocket for spare mirrors, 



and broad web shoulder 



strap IS O 



Spare mirrors ... each S2 6 



Postage I/- ; Foreign 2/- 



C. BAKER, Optician, 



(Established 1763) 



2ii HIGH HOLBORN, LONDON. 



NEWTON & Co.'s 



NEW ACADEMY LANTERN 



With Interchangeable Bellows Front, 

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£10 10s. Od. 



This is probably the very finest vahie 



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Write for Catalogue No. 4, Section H, 



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PLATES 



Correspondence Invited from those Interested In Astronomical, Botanical, Chemical, Geological, Medical, 

 Physical, and Zoological Phutographic Worli. 



ILFORD Limited, ILFORD, LONDON, E. 



Just published. 15/- net. 500 pp. 

 Numerous illustrations. 



Dante and the 

 Early Astronomers. 



By M. A. ORR 



(Un. JOHN EVERSHED. Eodaikaaal}. 



A study of the ideas of the early astronomers, and 

 their relation to mediaeval thought, as revealed in the 

 numerous astronomical references found in Dante's 

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NORTON'S STAR ATLAS 



A 



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 Positions for 1921. 



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CHCMICAI., PHYSICAL, and 



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J.Woolley,Sons&C& 



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CATALOGUES ON APPLICATION. 



Prism Binoculars 



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CLARKSON'S, 



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" Knowledge " may be obtained through any Bookstall or Newsagent. 

 Offices : — Avenue Chambers, Bloomsbury Square, London, W.C. 



