Oct. 1 6, 1879] 



NATURE 



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SUBSCRIPTIONS TO NATURE 



Yearly 28j. 



Half-yearly i+f. 6^. 



Quarterly 7J. (>d. 



To the Colonies, United States, the Continent, and 

 all places within the Postal Union ; — 



Yearly 30J. 6(i 



Half-yearly , IS J. dd. 



Quarterly %s. 



Office : 29, Bedford Street, Strand. 



Now ready, a Revised Edition. 



NEGRETTI & ZAMBRA'S 



ENCYCLOPAEDIC 



Illustrated, and Descriptive 

 CATALOGUE OF 



SCIENTIFIC INSTRUMENTS. 



(Containing very numerous Comparative Tables of Reference and 



Illustrated by upwardi of TWELVE HUNDRED ENGRAVINGS. 



Six Hundred Pages, Royal 8vo, cloth, gilt lettered. Price SJ. 6a'.) 



Oftical, Mathematical, Philosophical, Photographic, 



AND 



STANDARD METEOROLOGICAL 

 INSTRUMENTS. 



MANUFACTURED AND SOLD BY 



NEGRETTI AND ZAMBRA, 



opticians and Scientific Instmmml Makers to 



TheRoyalObservatory.Greenwich; the Admiralty ; Hon. Board of Ordnance 



Board of Trade ; the British Meteorological Society; the Observatories 



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



HOLBORN VIADUCT, E.C. 



ALSO AT 



46, CORNHILL, E.G., & 122, REGENT STREET, W., 

 LONDON. 



M. JACKSON & CO., 



(J. ORME and H. M. CAPNER) 

 MANUFACTURERS AND IMPORTERS OF 



SCIENTIFIC APPARATUS 



AND 



CHEMICALS. 



Sole Agents for Hickley's Patent Telephones, 



Price 50/. per Pair, Cash with Order. 



Price Lists sent on receipt of Three Stamps for Postage. 



For Trade Terms inclose Business Card. 



65, BARBICAN, LONDO N, E.G. 



ADAM HILGER, 



icniific Instrument Maker to the Royal Observatories 

 of Greenwich and Edinburgh, the Observatories of 

 Melbourne, Sydney, Potsdam, dr>c., Sr'c. 

 192, TOTTENHAM COURT ROAD, LONDON. 



Direct Vision Spectroscopes with adjustable light and high dispersive power, 

 in Brass Ca-se for waistcoat pocket, price £i $s. Ditto, large sizes, £2 and 

 £2 los. With Quartz I-enses, los. extra. Table Spectroscopes for Students, 

 from j^i los. Ditto, with 2 Prisms and divided line, from^rs. Half Prism 

 Spectroscopes with very high dispersive power etjual to 15 Prisms of 60", 

 on Brass Stands with Universal motion, complete m case, price from ^40. 

 Hilgcr's Variable Power Prisms for Spectral Analyses, with 6 different 

 ix.wers, from i'^ to 10°, from A to H, of light flint, price, in case, ^^5 ics. 



■V), with extra dense flint and a power from 1° to 25°, from A to H, price 

 los. Spherometers, in Morocco Case, from £$ loj. 



NEW ILLUSTRATED CATALOGUE of ELECTRIC 



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

 pest free, 6 Stamps. 



EDWARD PATERSCN, 



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 Descrtpiions for Lecture Purposes Loaned out. 

 APPARATUS for CLASS DEMONSTRATION and for SCIENCE 



SCHOOLS. 

 ELECTRIC 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 BELLS, WIRE, &c., for 



Fixing. 

 EDISON'S ELECTRIC PEN ;<;8 Si. 



ELECTRIC and MAGNETIC APPARATUS of all Descriptions. 

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

 do do Electric Signals, Part 2. Post free, 6 Stamps. 



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



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



WATER ANALYST, 



Performs every description of Water Analysis on moderate term?. 



Properly cleansed bottles for the reception of samples sent to any part of 



the Kiagdom. 



LIGHTNING CONDUCTOUS, 



Experience, accumulated since the time of Benjamin Franklin, proves 

 conclusively that a Conductor made of Copper of adequate size is the best 

 of all appliances for the protection of every description of building from the 

 destructive effects of lightning. 



NEWALL & CO.'S 



PATENT COPPER LIGHTNING GONDUGTOR, 



As applied to all kinds of Buildings and Shijjping in all parts of the world 

 with unvarying success, is the most Reliable, most Effective, and Cheapest 

 Conductor ever offered to the public. 



It is simple in its application, no insulators being required, and it costs 

 only one shilling per foot for the standard siae, which is safe in any storm. 



R. S. NEWALL & CO., 130. STRAND, W.C 



36, W.A.TERLOO ROAD, LIVERPvOOL. 

 63. ANDERSTON QUAY, GLASGOW. 

 MANUFACTOBY-GATESHEAD-ON-TYNE. 



W. F. STANLEY, 



Mathematical Instrument Manufacturer 



To H.M.'s Government, Council of India, Science and Art 

 Department, Admiralty, &c. 



Matiiematical, Drawing, and Surveying Instruments of every description, of 

 the highest quality and finish, at the most moderate prices. 



Price List post free. Engine Divider to the Trade. 

 ADDRESS- 

 GREAT TURNSTILE, HOLBORN, LONDON, W.C. 



NOTICE OF REMOVAL. 



JAMES HOW & CO., 



SCIENTIFIC INSTRUMENT MAKE'RS 



73, FARRINGDON ST.. LONDON 



(Late of 5, St. Bridb St., and a, Foster Lane). 



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



Rock Sections tnd other Objects for the Microscope. 



ELECTRIC BELLS AND HOW TO FIX 



THEMi Post free 6 Stamps. Price Lists of Electric Bel Upost free. 

 J. & W. E. ARCHBUTT, 8, Bridge Street. Westmmster. S.W. 



