A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



' ' To the solid g?'oiiud 

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



INDUCTION COILS. 



Messrs. NEWTON & CO., of 3 Flekt Street, London, 

 h;ivc made an arrangement with Mr. Kvvs t)y which the results 

 of his une<|ualled experience in large Coil making have been 

 fully placed at their disposal. 



As he has been unable to cope with the demand for these 

 instruments, .\pps' Talented Coils are now manufactured con- 

 currently by Messrs. Newton & Co. on their own premises. 



These Coils have for many years been acknowledged the best 

 and most eliicicnt in the world, and it is hoped that the high 

 quality of workmanship maintained in Messrs. Newton ..S; Co. 's 

 workshops may still further increase their reputation. 



All the Coils up to lo-inch are tested to considerably more 

 than the guaranteed length of spark. 

 Spark in air. £ s. 



1 in S S 



2 ,, 10 10 



3 ,, 12 12 



4 „ 15 15 



6 ,, (with pillars) 22 10 



All the above Coils are covered 



highest quality, and all are fitted with Commutator and five pairs 

 of Terminals so that they can be used with Primary Batteries or 

 Accumulators or direct from the main, and the Condenser can be 

 cut out if desired, which should be done when using alternate 

 currents. 



BECK YS MICROSC OPES. 



No. 2SA.— THIS MODEL, with 

 I -in. and J-in. Object Glas.ses, 

 Two Eyepieces, and packed 

 in Polished Mahogany Case, 



£6 IDs. 



No. 25B.— THIS MODEL, with 

 5-in. and J -in. Object Glasses, 

 Two Eyepieces, and packed 

 in Polished Mahogany Case, 



£7 5s. 



STAND No. 25. 



. 29B.^The addition of Abbe 

 Condenser to 25B with Iris 

 Diaphragm and Focussing 

 and Swinging Adjustments, 



£8 Ids. 



FULL PARTICULARS FREE on APPLICATION to 



R. & J. BECK, Ltd., 68 cornhill, London, e.c 



THE EYE 



Anatomically represented in a Coloured Sectional Chart, with 

 explanatory text. 



By DR. RENLOW. 



Revised and Edited, with an Introduction on Eyesight, by 

 JOHN BROWNING, F.R.A.S., F.R.M.S., 



President of the British Optical As.sociation, Author of "Our 

 Eyes," &c. 



This Chart shows, in twenty sectional parts, all the principal 

 parts of the Eye ; the Chart is about lo inches by 8 inches, and 

 is bound with twenty pages of letterpress and six engravings- 

 in the text. 



PRICE IS. bd. NET. 



Sent, Post Free, for 2s. 6if., hy 



MR. JOHN BROWNING, 



OPHTHALMIC OPTICIAN, 

 63 STRAND, LONDON, W.C. 



STTlVIlVtEI g. UOH .TP.A.'yS. 



NEGRETTI & ZAMBRA'S 



BINOCULARS AND TELESCOPES. 



1 of the "OFFICER OF THE WATCH" TELESCOPE, 

 in use on all the ve.ssels of H.M. Navy. 



£2 2s. 



£2 2s. 



As supplied by NEGRETTI & ZAtVIBRA to the War Office. 



Length, when closed, ii inches. Conibinin.s high power and portability. 



NEGRETTI &. ZAMBRA, 



SCIENTIFIC INSTRUMENT MAKERS to the QUEEN, 



38 HOLBORN VIADUCT, E.C. 



Branches: 45 CORNHILL; 122 REGENT STREET. 



Illustk.ited Pkice LisTi Fkee bv Pust. 



