A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



' ' To the solid ground 

 Of Nature trusts the mind which builds for aye."- 



-Wordsworth. 



NEWTON & CO. 



BROWNING'S PLATYSCOPIC LENS. 



With Larger Angles, Increased Field, and Improved Definition. 



RONTGEN X-RAY WORK. 



APPS COILS (Xeutuns makc)- 



i ill , *;12 12s.: f> in , £22 10s.; 



i in , £36 1 5s. 



FOCUS TUBES. 25s. c;„ 1, 



•FLUORESCENT SCREENS, 



i -,. 35s.: lu s, 63s. 



ROWLANDS STAND (.x. Fig.) fop 



Medical Use, £2 12s. 6d. 



3 FLEEJ STREET, 

 LONDON. 



PKICli LISTS i-REE. 



The Frena Camera 



«♦»♦♦♦♦♦•♦♦♦♦«««♦♦ 



PARTICULARS of this 



unique HAND-CAMERA 



may he had FREE on 



application to 



^ .. , R. & J. BECK. 



K.».»At}rti UP !• Hir LONDON, E.G. 



68 CORNHILL, 



E:itr>nzv,i K^nl \, , 



AN ACHROMATIC COMBINATION, 



COMBINING THE DEFINITION OF A .MICROSCOPE WITH THE 

 PORTABILITY OF A POCKET LENS. 



'* If you carry a sm.itl Platyscopic Pocket Lens (which every observer of 

 Nature ought to do)." — Grant Allen in Knowledge, 



The Platyscopic Lens is invaluable to botanists, mineralogists, or ento- 

 mologists, as it focuses about three times as far from the object as the 

 Codcfington Lenses. This allows opaque objects to be examined easily. 



The Platyscopic Lens is made of four degrees of power, magnifying 

 respectively lo, 15, 20, and 30 diams. ; the lowest power, having the largest 

 field, is the best adapted for general use. 



The Lenses are set in Ebonite Cells, and mounted in Tortoiseshell Frames 



Price of the Platyscopic Lens , mounted in Tortoiseshell, magni- 

 fying either 10, 15, 20, or 30 diameters, iS.r. 6d. each power. 

 Illiistiated description sent free. 



JOHN BROWNING. 63 STRAND. LONDON, W.C. 



NEGRETTI & ZAMBRAT 



SOLE MAKERS OF 



JORDAN'S (PATENT) SUNSHINE RECORDER. 



New Simplified Model, 

 adjustable for any 

 latitude, and tho- 

 roughly efficient. 

 Price £1 7s. 6d. 



Sensitised Charts, 

 5s. per 100. 



NEGRETTI 

 ZAMBRA, 



Scientific Instrument 

 Makers to the Queen^ 



38 HOLBORN VIADUCT. 



Branches— 45 Cornhill^ 



122 Recent Street,- 



LONDON. 



ILLUSTRATED DESCRIPTION POST FREE. 



Telephone No. 6583. Telegraphic Address, " Negretti. London.' 



