A WEEKLY ILLUSTRATED JOURNAL OF SCI 



" To the solid ground 

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



BUY DIRECT FROM 



F E BFCPCEI? & CO hatton wall. 



John J. GRIFFIN &SOf 



MAKERS OF 



Physical Apparatus 



THE GRAY-BURNSIDE 



MOTOR GYROSTAT 



for demonstrating all the properties and 

 practical applications of the gyrostat. 



GYROST ATIC PEN DULUM 

 GRAY'S GYROSTATIC MODELS 



As demonstrated at the Physical Society. 

 PRICES OS AITLICATTOX. 



Kemble St. KINGSWAY London, W.C. 



GRAND PRIX AWARD, TURIN. 1 11. 



SOLE .\UTHORISED MAKFRS OF 

 STROUD & RENDELL SCIENCE LANTERNS. 



The "University" Lan- 

 tern, with Russian iron 

 body, sliding baseboard, two 

 superior objectives, plane 

 silvered mirror "A," which 

 d by a knob causing 

 tne rays to be reflected 

 upwards for the projection 

 of obj.cls in a horizontal 

 plane, condensers 4J in. diam., 

 prism with silvered, back 

 be used at "C," 

 erecting prism 

 "D," lime-light 

 ie carrier. Price 

 1 travelling case, 

 .table 



£10 



... 11 15 

 adjustable table " B" for supporting apparatus, extra 7 



The " College " Lantern, without adjustable table, with 



lime-light burner complete 8 2 



Ditto, diiio, with "Pha;n' ■ ■ - - 



Slit and prism for spectru 



Polariser and analyser 2 1 



Catalogues post free. 



A Optical Lanterns and Accessory Apparatus. 223 pages, 

 bridged List of Chemical Apparatus and Chemicals. 44 pages. 



support, tor either lante 



Me 



nical Models for t 

 Con 



ilding : 



nd machil 



4 coiyiiyii3RCiA.i:^ stkeet, il.e:e:i3s. 



NEGRETTI & ZAMBRA'S 

 RECORDING RAIN GAUGES. 

 The"Hyetograph" 



has but 3^ moving 

 parts, viz., the float, 

 the pen arm, and 

 the clock drum. It 

 is, therefore, simple. 



Price, complete, with 



charts, pen, and iuk, 



S6 15 



/lluslraleJ Price List of 

 Rain Gauges, etc., sent 

 post free on request. 



38 Holborn Viaduct, 



London, E.G. 



45 Cornhill, E.G. 



122 Regent St., W. 



