KNOWLEDGE. 



March, 1915. 



Symons's Meteorological Magazine. 



Edited by HUGH ROBERT MILL, D.Sc. 



This Illuslrated Magazine, founded in 1866, is devoted to the science o. 

 Meteorology- in all its branches. 



The monthly Climatological Table of the British Empire and the monthly 

 Rainfall Map of the Thames Valley are unique features. Special attention 

 is given to Correspondence from Meteorologists and Observer.*^ The 

 meetings of Meteorological Societies are punctually reported. All important 

 Books bearing on Meieorolog>' are reviewed. Original Articles and 

 descriptions of New Apparatus frequently appear. Exceptional Conditions 

 of Weather in the British Isles are discussed while still remembered. 



Publisbed on the i6th of each month. Price 4^^., 

 annum post free to any part of the world. 



or 5s. per 



A Specimen Number will be sent free on application to the 

 Editor at 62, Camdea Square, London, jV. H'. 



Published by EDWARD STANFORD, Ltd. 

 Acre, London, W'.C 



12, 13, & 1 4, Long 



POPULAR ASTRONOMY. 



TWENTV=ONE VOLUMES COMPLETED. 



A Journal for Reference on Current Astronomy. 



Over 500 



Pages of Reading Matter fully 

 each Volume. 



Illustrated in 



Containing the Latest Astronomical News. Articles on 

 Astronomical Themes. Many Fine Engravings. Spectro- 

 scopic, Planet and Comet Notes. Star Charts everj' Month. 



A Valuable Journal in any General Library. 



Subscription to the Twenty-second Volume (ten numbers) post free to any address 

 in the United States on receipt of 3 dollars 50 cents; Canada, 3 dollars 75 cents; 

 and 16s. 6d. for all other countries. Preceding volumes at same price. 



Editors: HERBERT C. WILSON, R.\LPH E. WILSON, and 

 CURVIN H. GINGRICH. 



GOODSELL OBSERYATORY OF CARLETON COLLEGE, 

 NORTHFIELD, MINN., U.S.A. 



WILLIAM WESLEY & SON, 28 Essex Street, Strand, London. 



BIRKBECK COLLEGE, 



BKE.A.MS BUILDINGS, C1L\NCEKV L.\NE, E.G. 



COURSES OF STUDY (Day and Evening) for Degrees of the 

 UNIVERSITY OF LONDON in the 



FACULTIES OF SCIENCE & ARTS 



(PASS AND HONOURS) 

 under RECOGNISED TE.\CHERS of the University. 



SCIENCE.— Chemistry, Physics. Mathematics (Pure and Applied), 

 Botany. Zoology. Geology. 



ARTS.— Latin, Greeii, English, French. German, Italian, History, 

 Geography. Logic, Economics, Mathematics (Pure and Applied). 



Eveaiag Courses for the Degrees la Economics and Laws. 



POST-GRADUATE AND RESEARCH WORK. 



SESSIONAL FEES: f ^"^ •■.Sci'=n«, fil 7 lOs.: Arts, «10 10S. 



t iLvening-; bcience. Arts, or Kconomics, £5 Ss. 



MATRICULATION COURSES AND ACCOUNTANCY. 



Prospectuses post free, Calendar ^d. {by post ^d.), /ram the Secretary. 



GLEW'S 



SCINTILLOSGOPE 



(Patent) 



MOWS a magnificent display of scintillations, 

 showers of sparks, direct from the mineral 

 Pitchblende, Radium, Polonium, Uranium, Thorium, 

 or any radio-active substance; even an Incandescent 

 CJas ^lantle contains sufficient Thorium to excite the 

 very sensitive screen of the Scinlilloscope, which is far 

 more sensitive than the Spinthariscope. The Scintilloscope rivals the 

 most delicate Electroscope as a detector of Alpha rays. 



The eye sees an inexhaustible shower of stars of while light, giving a very 

 realistic idea of the ceaseless activity of these marvellous substances which are 

 producing the terrific bombardment causing this beautiful display. 



GLliW'S SCINTILLOSCOPE, Superior Lens, with Extra-sensitive Radium 

 and Pitchblende Screens, giving brilliant effects. Complete, 7s. 6d., Post free, U.K. 

 Foreign Postage extra, weight 2 ounces. 



Pieces of Pitchblende mineral, ground flat and polished, with Sensitive Screen 

 attached, for use in Scintilloscope or with any strong pocket magnifier, from 

 7s. 6d. each, according to size. 



F, HARRISON GLEW (Patentee), 156, Clapham Road, London, S.W. 



TELESCOPES. 



THE "LORD BURY" TELESCOPE, bronzed brass, in sling case £4 4 



Size, closed, lo inches; exiended, 31 inches. Diameter of Object Glass, \\ inches. 



Magnifying power 25 diameters, increasing by pancratic tube to 35 diameters. 



AnguUir Field \-^°. Lateral Field .at 1,000 yds. = 26-2 yds. 



Will show a Flagstaff at 22 miles. I Will make out Wild Fowl at 16 miles. 



,, read name of Lightship at 9 miles. ' ,, show time by Church Clock at 6 miles. 



THE STEWARD 

 PRISM BINOCULAR 



£5 ISO in sling case. 



Central focussing adjustment. Sealed bodies. 

 Suitable for use in hot climates. 



Magnifying Power 

 Angular Field .. 



X 8 diameters. 



5' 



Either of the above sent post free on 



receipt of remittance. 

 Illustrated Catalogue, Part I, post free. 



J. H. STEWARD, Ltd. opticians to the BHtish and 



406 STRAND; 



Foreign Governnnents, 

 457 WEST STRAND, LONDON. ^^52" 



WaTKINS and 

 DONCASTER, 



N ATURALI STS 

 and Manufacturers of 



Cabinets and 

 Apparatus :: 



- FOR - 



COLLECTORS OF INSECTS, BIRDS' 



EGGS AND SKINS, MINERALS, 



PLANTS, Etc. 



Lovers of Birds who wish to 

 encourage them to nest in their 

 gardens or shrubberies should 

 apply for our Price List of Nestmg 

 Boxes. 



A LARGE STOCK OF INSECTS, 

 AND BIRDS' EGOS AND SKINS. 



SPECIALITY.— Objects for Nature 

 Study, Drawing Classes, cSc. 



Birds, Mammals, etc.. Preserved and Mounted by 

 First-clais Workmen true to Nature. 



tW All Books and Publications on Natural 

 History supplied. 



36, Strand, London, W.C. 



(Five Doors from Charing Cross.) 



CATALOQUB POST FRBB. 



