6'^6'-V'^ 



A WEEKLY lLL.olk..x..ij juUlvNAL OF SCIENCE. 



" To the solid ground 

 Of Nature trusts the m'hid which builds for aye." — Wordsworth. 



No. 1665, Vol. 64] 



THURSDAY, SEPTEMBER 26, 1901. 



[Price Sixpence. 



Newspaper at the General Post Office.] 



Dr. J. H. YINCENT'S 



PHOTOGRAPHS OF RIPPLES. 



(COrVRlGHT.) 

 Messrs. Xewtox & Co. have purchased the Negatives of 

 the Ripples, and are publishing Lantern Slides of these interest- 

 ing Researches, illustrating Acoustical and Optical Phenomena, 

 by Photographs of Ripples on the Surface of Alercury and Water. 



44 Slides Is. 6d. each. 



The Magnetic Field. 



A Series of Direct Photographs showins the Lines of Korce in the Magnetic 



Field. 



10 Slides Is. each. 



Sound Waves. 



From Negatives by Prof. R. W. Wood, U.S.A. 



16 Slides Is. 6d. each. 



Flying Bullets. 



From Negatives by Prof. C. V. Bovs. 



12 Slides 2S. 6d. each. 



Electrical Discharges. 



From Negatives by .-V. .\. C. Swinton, Esq. 



6 Slides Is. each. 



Wireless Telegraphy. 

 25 Slides .. Is. each. 



LIST OF SLIDES FOR SEASON 1901-2 POST FREE. 



NEIW^TON <& CO., 



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This rapid, wide, medium or narrow angle lens all in one is 



suitable for all work. 



I^ull Catalog^te free on application to the ATamifactiirers : — 



R. & J. beck:, Lta., 



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SPECTACLES 

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Iltiistrateil Price Lists o/ Optical and Meteorological Imtrum 

 Free tv Post to nil /.arts of the M'orU. 



NEGRETTI and ZAMBRA, 

 38 HOLBCRN VIADUCT, E.C. 



