A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE 



BROWNING'S 



INDUCTION GOILS. 



MR. JOHN BROWXING begs to inform scientific gentlemen that the adoption of an improved method of 

 winding Induction Coils has enabled him to increase their efficiency and reduce their cost. Every Coil is 

 guaranteed to give the length of spark named. 



Induction Coil, to give a J in. spark in dry air, £3 53. ; to give a I in. spark, £5 lOs. ; to give a l^ in. spark, 

 £6 15s. ; to give a 2i in. spark, £10 ; to give a 3i in. spark, £12 15s. ; to give a 4j in. spark, £16 ; to give a 6 in. 



... -«„. , -- €>- - ~ — -Z ~t 7 •WAV'} vw^..v,..»j^».*. ^^^«,nj otiJL^ A*- 



spark, £22 ; to give a 9 in. spark, £36 ; to give a 12 in. spark, £45. 





LIST OF ELECTRIC LAMPS AND LANTERNS AND GALVANIC BATTERIES SENT FREE. 



JOHN BROWNING, 



OPTICAL AND PHYSICAL INSTRUMENT MAKER TO H.M. GOVERNMENT, THE ROYAL SOCIETY, THK 



ROYAL OBSERVATORIES OK GREENWICH AND EDINBURGH, AND THE OBSERVATORIES OF 



KEW, CAMBRIDGE, DURHAM, UTRECHT, MELBOURNE, &c., *c. 



63, STRAND, ■W.C. 



FACTORY— SOUTHAMPTON STREET, LONDON, W.C. 



