,August 28, 1879] 



NATURE 



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SUBSCRIPTIONS TO NATURE 



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Yearly 3cm. 6rf. 



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Office : 29, Bedford Street, Strand. 



WANTED, Clean Copies of NATURE, No. 472, 

 for Noveinher 14, 1878. Address — Office oj 

 NATURE, 29, Bedford Street, Strand. 



EAGLE INSURANCE COMPANY, 



79, PALL MALL. 

 For Livbs only. Established 1807. 

 Net Premiums and Interest ...»,.«»..»». ;f 396,818 

 Accumulated Funds ... ^ ,.,... ... ... ... ... j£3,o83.38i 



Also a Subscribed Capital of more than ... .« ^1,500,000 



Reports, Prospectuses, and Forms may be had at the Office, or from any 

 of t^ie Company s Agents, post free. 



GEORGE HtJMPHREYS, Actuary and Secretary. 



W. L A D D & CO.. 



Scientific Instmment Manafactiirer£ 



(By appointvient to the Royal Institution of Great Britain), 



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



BYRNE'S PATENT COMPOUND PLATE PNEU- 

 MATIC BATTERY for Cautery and general purposes. 



EDMUNDS' PHONOSCOPE for making Vocal Vibra- 

 tions visilile in a Vacuum Tube. 



HUGHES' MICROPHONE. 



TELEPHONIC APPARATUS, &c. 



LADD'S IMPROVED SELF CHARGING HOLTZ 

 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. 



rliuitrated Catalogue, Sixpence. 



EUDOLPil KOENIG, 



(Dk. PHIL.) 

 MANUFACTURER OF 



ACOUSTICAL INSTRUMENTS. 



TO ILLUSTRATE THE LAWS 

 AND TO PRODUCE THE PHENOMENA OF SOUND. 



PARIS. 26, EUE DE PONTOISE. 



PRICE LISTS FREE. 



LIGHTNING CONDUCTORS. 



Ejcpericncei accumulated since (!•« time o£ Benjamin Franklin, proves 

 conclusively that a Contluctor madt of Copper of adequate siM is the best 

 of all appliances fur the protectior ^^ every description of buUdioK from the 

 destructive effects o£ liKhtniue. 



NEWALL & GO.'S 



PATENT COPPER LU^HTNING CONDUCTOR, 



As applied to all kinds oC ButUliu^ tin! ShipfMnK In all parts of the world 

 with unvarying success, is the lI.v•^t Reliable, most Effective, and Cheapeit 

 Conductor ever offered to the public. 



It is simple tn its application, ii< wi^uiators bein( required, and it costs 

 only one shilling per foot for iht ^tiil^l.u> >i«c, which is safe in any storm. 

 R. 8. NEMTAIfli ds CO., i aVD, W.C. 



r ' 1 .' )0 ROAD, LIVERPOOL . 



• r . K .s TON QUAY, GLASGOW. 

 MANUFAOTOBY^&ATBSHBAD-ON-TYNB 



Now ready, a Revised Edition. 



NEGRETTI & ZAMBRA'S 



ENCYCLOPAEDIC 



Illustrated and Descriptive 

 CATALOGUE OF 



SCIENTIFIC INSTRUMENTS. 



(Containing very numer.us Comparative Tables of Reference and 



Illustrated by upwards of TWELVE HUNDRED ENGRAVINGS, 



Six Hundred Pages, Royal 8vo, cloth, gilt lettered, Price is. id.) 



Oftical, Mathematical, Philosophical, Photographic, 



AND 



STANDARD METEOROLOGICAL 

 INSTRUMENTS. 



MANUrACTORED AND SOLD BY 



NEGRETTI ANI> ZAMBRA, 



Opticians and Scientific Instntment Makers to 



The Royal Observatory, Greenwich; theAdmiraUy; Hon. Board of Ordnance; 



Board of Tnade ; the British Meteorological Society; the Observatories 



Kew, Toronto, Washington, Victoria; East Indian Government. 



HOLBORN VIADUCT, B.C. 



ALSO AT 



45, CORNHILL, E.G., & 122, REGENT STREET, "W., 

 LONDON. 



NOTICE OF REMOVAL. 



JAMES HOW & CO., 



SCIENTIFIC INSTRUMENT MAKERS, 



73, FARRINGDON ST., LONDON 



(I.,ATE OF 5, St. Bride St., and 2, Fo.ste:i Lane). 



HOW'S STUDENT'S MICROSCOPE. HOW'S MICROSCOPE LAMP. 



Rock Sections and oth^r Objects for the Microscope. 



NEW ILLUSTRATED CATALOGUE of ELECTRIC 



SIGNALS. &c., with Instructions for Fixing. 150 Diagrams. Justout, 

 post free, 6 Stamps. 



EDNA/ARD PATERSON, 



Electrical Engineer and Scientific Apparatus Manufacturer, 



3, BEDFORD COURT, COVENT GARDEN, LONDON 



STEAM WORKS, GRAY'S INN ROAD. 



Experiments in Electric Lighting carried out. 



Electrical Apparatus of all Descriptions for Lecture Purposes Loaned out, 



APPARATUS for CLASS DEMONSTRATION and for SCIENCE 



SCHOflLS. 

 ELECIRIC LIGHT APPARATUS. 

 SIEMEN'S and GRAMME'S DYNAMO MACHINES and LAMPS 



for Hire and Purchase. 

 LARGE ASSORTMENT of RUHMKORFF COILS and VACUUM 



TUBES. 

 PROFESSOR HUGHES' MICROPHONE. 

 ELECTRIC BELLS and INDICATORS. 

 TELEPHONES and TELEPHONE CALL BELL.S, WIRE, Stc, for 



Fixing. 

 EDISON^S ELECTRIC PEN i% %s. 



ELECTRIC and MAGNETIC APPARATUS of all Descriptions. 

 Illustrated Catalogue Electrical Apparatus, Part t. Post free. 6 Stamps, 

 do do Electric Signals, Part 3. Post free, 6 Stamps. 



LABORATORY, 38, GRACECHURCH STREET, LONDON, E.G. 



A. ANTHONY NESBIT, F.C.S., 



WATER ANALYST, 



Performs every description of Water Analysis on moderate terms. 



Prtperly cleansed bottles f .r tlie reception of samples sent to any part ef 



the Kiogdom. 



