A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE 



" To the solid ground 

 Of Nature trusts the mind which builds for aye." — Wordsworth. 



CALCULATING SLIDE RULE.! GLEWS SGINTILLOSCOPE 



Best and Cheapest, 



JSxi^in.e-di'viclecl oix Cellu.loid. 



10" Rule, with Cursor, in Case, with Directions, xo/6. 



Useful for multiplication, division, evolution and in\oIution, for c 

 puting strength of beams, moments of inertia, horse-power of engi 

 hydraulic formulas, areas of circles and ellipvcs, cubic contents, weights, 



puttincj down a single intermediate quantity. Problems involving the ap 

 plication of Ohm's Law of the relation between current, eleciro-motivt 

 force, and resistance. Surveys by rectangular co-ordinates and set-oui 



NEWTON & CO., 3 FLEET ST., LONDON. 



CI^X^I 



Improved Pattern 



IMERNST 



PROJECTION 



LAMPS 



with 



Electrical Heating 



Circuit. 



Double 



filament 

 carrying 

 2 amps. 



lh-,inftu\ I\,i„phi,t /\'sl /•;■,,■ ,.;/ application to 



JOHN J. GRIFFIN & SONS, Ltd., 



20-26 SARDINIA STREET, LONDON, W.C. 



(Pa 



:ing the 



Shows a magnificent display ot scintillations, 

 showers of spaiks, direct from the mineral Pitch- 

 blende, Radium, Polonium, Uranium, Thorium, or any 

 radio-active substance, even a Weisbach mantle con- 

 tains sufficient Thorium to excite the very sensitive 

 screen of the Scintilloscope, which is far more sensi- 

 tive than the Spinthariscope. 'Ihe Scintilloscope 

 H; rivals the most delicate Electroscope as a detector 

 >f .Alpha lais. 



The eye sees an inexhaustible shower of stars of 

 vlite light, Biving a very realistic idea of the ceaseless 

 iclivity of these marvellous substances which are pro- 

 ■ific bombai. ment causing this beautiful display. 

 Wm- See Nature, September 29, page 535. 

 Glew's Scintilloscope Superio T.ens, with Extra-sensitive Pitchblende and 

 Polonium Screens, giving brilliant effects, Complete, js. 6d., Post free, 

 U.K. Foreign Postage extr , weight 2 ounces. 

 Pieces of Pitchblen.le mineral, ground flat and polished, with Sensitive 

 Screen attached, for use in Scintilloscope or with any strong pocke 

 magnifier, frOTi -js. 6d. each, according to size. 

 Radir. ctive supplies of every description, on Sale or Hire. Radiur 

 Bromide 1,800,000 units on hire lor lectures. 



F. HARRISON GLEW, Radiographer 



(Silver .Mtdallist, Paris, 1900), 



156 CLAPHAM ROAD. LONDON, S.W. 



NEGRETTI & ZAMBRA'S 



ANEROID 

 AROIVIETERS. 



NEW ILLUSTRATED AND 



REVISED PRICE LISTS 

 Free by Post. 



The Watcn Size 

 Aneroid for foreiellin;i 

 weatti^^r and measur- 

 ing heights. 



38 



Holborn Viaduct, 



E.C, 

 nnclK-s— 

 45 Corithill: 

 13'J Re/rnt tit 1 ex!. 



