May 1, 1879] 



NATURE 



yH 



PROFESSOR FULLER'S SPIRAL SLIDE RULE 



For Multiplication, Division, Extraction of Roots, &c., up to 5 Figures, 

 equivalent to an ordinary slide rule 83 feel long. 



PRICE SOS. 

 STANLEY, 



MATHEMATICAL INSTRUMENT MAKER, 

 Great Turnstile, Holborn, London. 



NONA/' READY, 

 SECOND EDITION, 



GRIFFIN'S 



CHEMICAL HANDICRAFT. 



PRICE ^s. 7J. POST FREE. 



A CATALOGUE OF CHEMICAL APPARATUS: 



ILLUSTRATED, CLASSIFIED, DESCRIPTIVE. 



Demy 8vo, 480 pp.. Illustrated with 1,600 Woodcuts. 



Most Complete and Cheapest List of Apparatus. 



JOHN J. GRIFFIN and SONS, 22, GARRICK STREET, 

 LONDON, W.C. 



EDWARD PATERSON, 



Electrical Engineer and Scientific Apparatus Manufacturer, 



3, BEDFORD COURT, COVENT GARDEN, LONDON. 



STEAM WORKS, GRAVS INN ROAD. 



Zzperiments in Electric Lighting carried oat 



Electrical Apparatus ef all description! for Lecture Purposes 

 Loaned out. 



APPARATUS FOR CLASS Demon- 

 stration and for SCIENCE SCHOOLS. 



ELECTRIC LIGHT APPARATUS. 

 SIEMEN'S and GRAMME'S DYNAMO 



MACHINES and LAMPS for Hire and Purchase. 



LARGE ASSORTMENTofRUHMKORFF 



COILS and VACUUM TUBES. 



PROFESSOR HUGHES' MICROPHONE. 

 ELECTRIC BELLS and INDICATORS. 

 TELEPHONES and TELEPHONE CALL 



BELLS, WIRE, &c., for Fixing. 



PROF. S. P. THOMPSON'S LANTERN 



SLIDE GALVANOMETER, 20J. 



EDISON'S ELECTRIC PEN £8 8s. 

 ELECTRIC and MAGNETIC APPA- 



RATUS of all Descriptions. 

 New Illustrated Catalogue of do pages post free 6 stamps. 

 Orders over ^% carriage paid to any part of the United Kingdom. 



GOLD MEDAL, 



PARIS EXHIBITION. 



In Packets and Tins. Pure 



Cocoa only, with the super* 



fluoufl oil extracted. 



FRYS 



COCOA 



*' If properly prepared, there is no nicer 

 or more wholesome preparation of 

 cocoa." — Food^ Water ^ and A tr, 

 edited hy Dr. Hassall. 



EXTRACT 



J. S. FRY & SONS, Bristol and London. 



HOLLOWAYS PILLS 



THIS 



MEDICINE 



Is a Certain Cure for aU Diiorders of the LIVEB, STOUACH 

 AND BOWELS. A Great PITBIFIEB of the BLOOD; • 

 Powerful luvigorator of the Systipm, in cases of WEAKNESS 

 ASO DEBITJIY, ud U nneanaUed in Female CoBpIaiuta, 



W. L A D D & CO., 



Scientific Instrnment Manafactarers 



iBy Appointttunt to tfu Royal Institution of Great Britaiti^ 



II & 12, BEAK STREET, REGENT STREET, W. 



BYRNE'S PATENT COMPOUND PLATE PNEU- 

 MATIC BATTERY for Cautery and general purposes. 



EDMUNDS' PHONOSCOPE for making Vocal Vibrar 

 tions visible in a Vacuum Tube. 



HUGHES' MICROPHONE. 



TELEPHONIC APPARATUS, &c. 



LADD'S IMPROVED SELF CHARGING HOLT2 

 ELECTRICAL MACHINE, with 4 to 12 Plates, in- 

 closed in a Mahogany and Glass Case. This instrument is 

 immediately available in any condition of the atmosphere. 

 Philosophical Apparatus of every Description. 



Ilbtsirated Catalo[iu, Sixfnei. 



3. C. TI8LEY cfe Co. 

 0PTICIAN8. '' 



172, BROMPTON ROAD, S.W. 



(Close to South Kensington Museum). 



THE PHONEIDOSCOPE 



An Instrument for Observing the Colour-Figures of Liquid Films under the 

 action of Sonorous Vibrations. 



Being a visible demonstration of the Vibratory and Molecular Motion of a 

 Telephone Plate. 



The PHONEIDOSCOPE, with 3 Discs, Bottle of Solution, Descriptive 

 Pamphlet, &c., in Cardboard Box, xos. 6d. 



MANUFACTURED AND SOLD WHOLESALK AND RETAIL BY 



S. C. TISLEY & CO.. 172. BROMPTON ROAD, LONDON, S.W. 



TELEPHONIC ELECTRICIIY. All Materials supplied for experi- 

 mental purposes. 



Price Lists of EUctrieal and Acoustic Apparatus, "with Dtavnnis an<i 

 Description 0/ the Harmono^aph^ Post Free, ltd. 



ENGRAVINGS AND ELECTROTYPES 



FOR SALE, at prices ranging from zs. to tos.y in good condition, ready for 

 printing. Small, medium stxe, and large engravings, comprising a great 

 variety of subjects, suitable for Publishert, Advertisers, and Amateurs. 

 Specimen of any subject required sent post free on application. 



FACSIMILE OF SIGNATURE for 3*. An exact copy of any Dane 



fiiaranteed. These signatures being engraved in bold relief, are useful for 

 tamping Books, Circulars, and Documents, or Marking Linen, and made 

 type-nigh for ordinary Letterpress Printing. 

 Sent post free to any address on receipt of 36 stamps. 



FLEET STREET, LONDON, E.G. 



ARTISTIC— To Ladies and Gentlemen with 



some leisure time, desiring to supplement their incomes, an opportunity 

 is offered of acquiring the ART of DRAWING and ENGRAVING 

 on WOOD in a thoroughly satisfactory and perfect style. The terms 

 are moderate, and the hours can be made to suit the convenience of 

 pupils. Persons residing in the country can receive full instruction by 

 correspondence. For further particulars call or address Mr. J. Frank- 

 lin Nash, Artist and Engraver, 75, Fleet Street, London, E.C 



OLDRIDGE'S BALM OF COLUMBIA 



Prevents Baldness and the Hair turning Grey, and forms tlie 



Basis of a Magnificent Head of Hair, Strengthens Weak Hair, 



and causes the 



WHISKERS AND MOUSTACHIOS to GROW FREELY, 



Sold everywhere, 3^. 6d., 6s. 6d., and ll-f.. 



Wholesale and RetaU. 



M, WELLINGTON STREET, STRAND, LONDON, W.C. 



ESTAILISKKD SiXTY YlAIS. 



