A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. Q0J gQ 19i2 



" To the solid ground \ 



Of Nature trusts the mind which builds for aye." — Wordsworth. \^ V- 



No. 2242, Vol. 90] 



THURSDAY, OCTOBER 17, rgia 



General Post Office 



[All Rights Reserved. 



Wheatstone's Compound Gyroscope 



PACKED IN CABINET CASE. 



Illustrated Price List of Gyroscopes 

 to be had post fiee fiom 



NEWTON & CO., Opticians to H.IVl. King Ceorge V. 

 72 WIGMORE STREET, LONDON. W. 



BECK'S FOCOSTAT LENS 



(Hiscorrs patent). 



to the 



Mapping Pen or Needle. ; 

 (focostat). Those who ha\ 

 glass or a lens on a stand 

 Being fixed on the instriin 

 'ith the instru 



tntomologist, Zoologist. 

 Botany and Dissecting, complete 



ting Instrumen' 

 /hen once set is always in focu 

 herto used a watchmaker's eye 

 appreciate the advantage of thii 

 itself, it is always in focus, as : 

 It is invaluable to the Botanist 



nd the Draughts 

 /ith Needle .. 



Scalpels with fine pointed Blades 

 Draughtsmen, complete with Mapping Pens 



REYNOLDS & BRANSON, Ltd. 



.•I r,vir./j- fTailu-d in iQir/ov S.knli/h Af'par.iuis — 

 GOLD MEDALS: LONDON. 1908. ALLAHABAD. 1911. 



GRAND PRIX. TURIN. 1911. 2 MEDALS. YORK. 1912. 



" RYS rOS " OPTICAL BENCH 



For use with the Stroud iS Rendell Science Lantern. 



R. & J. BECK, Ltd., 68 CORNHILL, LONDON, E.C. 



Optical Ben. h for lantern, one metre lun;;, uiiliuut fittings, £1 10 0. 



Sliding tables, 4/6 each. Lens holders, 5,6. Adjustable slit, 4/9. 



Screeii holder, 4/- Standard candle holder, 1/- Circular table. 1/6. 



Screen with gauze, 3/6. Half-metre extension with foot, 12/6. 



The above can also be u~ed without the lantern ,is an ordinary optical 



bench, and any part can be supplied separately. 



Descriplice Circular of Accessory Apparatus for the 



■■ 5. 6- R." lantern, post free. 



14 coivmaExcciA.!^ s'X'KiiiiE'r', ]l.e:e:i>s. 



NEGRETTI & ZAMBRA'S 



Standard Meteorological Instruments 



38 Holborn Viaduct. 



London, E.C. 



45 Cornhill, E.C. 



122 Regent Street, W. 



