Jtdy 3, 1879] 



NATURE 



Ixxvii 



DIARY 



OF SOCIETIES. 



London 



THURSDAY, Jri-Y 3. 

 Gkouxiists* Association, at 8. 



MONDAY, July 7. 

 Royal Institltion, at 5.— General Monthly Meeting. 



TUESDAY, JuLV 8. 

 West London Scientific Association, at 3. 



FRIDAY, July ii. 



QUKKETT M ICROSCOPICAL Club, at 8, 



SUBSCRIPTIONS TO NATURE 



Yearly 28J. 



Half-yearly 14J. 6rf. 



Quarterly Ts. 6(1. 



To the Colonies, United States, the Continent, and 

 all places within the Postal Union : — 



Yearly 'ios. 6d. 



Half-yearly i^s. 6d. 



Quarterly 8s. 



Office : 29, Bedford Street, Strand. 



THIN GLASS FOR MICROSCOPIC 



MOUNTING, of best quaKty. Circles, 31. 6rf. per ounce ; Squares, 

 2X. 9^. : post free 2(/. extra ; Ground edged Slips, 5*. per gross : also 

 other Mounting Materials and Objects prepared for mounting.— CHAS. 

 PETIT. 151, High Street. Str.ke N'ewin gton. N. 



W. F. STANLEY, 



Mathematical Instrument Manufacturer 



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



Department, Admiralty, &c. 



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



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



Ptiie List post Jree. Engine Divider to the Trade. 

 ADDRESS- 

 GREAT TURNSTILE, HOLBORN, LONDON, W.C. 



BUDOLPH KOENIG, 



(DR. PHIL.) 

 MANUFACTURER OF 



ACOUSTICAL INSTRUMENTS. 



TO ILLUSTRATE THE LAWS 

 AND TO PRODUCE THE PHENOMENA OF SOUND. 



PARIS, 26, RUE DE POHTOISE. 



PRICE LISTS FREE. 



NO\/V READY, 

 SECOND EDITION, 



G R I F F I N'S 



CHEMICAL HANDICRAFT. 



PRICE ^s. id. POST FREE. 



A CATALOGUE OF CHEMICAL APPARATUS: 



ILLUSTRATED, CLASSIFIED, DESCRIPTIVE. 



Demy 8vo, 480 pp. , Illustrated with i.fioo Woodcuts. 



Most Complete and Cheapest List of Apparatus. 



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

 LONDON, W.C. 



LIGHTNING CONDUCTORS, 



Experience, accumulated sinc« the time o£ Benjamin Franklin, prorei 

 conclusively that a Conductor made of Copper of adequate sire is th« b«st 

 of all appliances for the protection o£ every description of building &om tbe 

 destructive effects of lightning. 



NEWALL & OO.'S 



PATENT COPPER LIGHTNING CONDUCTOR, 



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

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

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

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



R. S. nWffKLl. ft CO., 130, STRAND, W.C. 



36, WATERLOO ROAD, LIVERPOOL. 

 63, ANDERSTON QUAY, GLASGOW. 



MANUFACTORY— SATESRB M>-ON.TYN& 



Now ready, .1 Revised Edition. 



NEGRETTI & ZAMBRA'S 



ENCYCLOP.EDIC 



Illustrated and Descriptive 

 CATALOGUE OF 



SCIENTIFIC INSTRUMENTS. 



(Containing very numerous Comparative Tables of Reference and 



Illustrated by upwards of TWELVE HUNDRED ENGRAVINGS, 



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



Optical, Mathematical, Philosophical, Photographic, 



AND 



STANDARD METEOROLOGICAL 

 INSTRUMENTS. 



MANUFACTURED AND SOLD BY 



NEGRETTI AND ZAMBRA, 



opticians and Scientific Instrument Makers to 



The Royal Observatorj', 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.G. 



ALSO AT 



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

 LONDON. 



'DRAPER'S INK (DICHROIC). 



THE NEW BLACK INK 



DIFFERING FROM ANYTHING ELSE EVER PRODUCED. 

 Writing becomes a pleasure when this Ink is used. It h.is been adopted 

 by the principal Banks, Public Offices, and Railway Companies throughout 



Ireland. 

 It writes almost instantly Full Black. I Flows easily from the Pen. 

 Does not corrode Steel Pens. Blotting-paper may be applied at the 



It cle.anly to use, and not liable toBIot 1 moment of writing. 



Can be obtained in London, through Messrs. Barclay & Sons, Farring- 

 don Street; W. Edwards, Old Change; F. Newbery & Sons, Newgate 

 Street; Wm. Mathbr, London and Manchester; J. Austin & Co., Duke 

 Street, Liverpool ; and Stacy & Cook, Paternoster Row ; and to be had of 

 all Stationers. . „ , ,. 



BEWLEV & DRAPER (Limited), Dublm. 



PROFESSOR HUGHES' AUDIOMETER. 



The only perfect measurer for testing the hearing power. Vide DR. Richardson's Report to the Royal Society, 

 May 15, 1879 ; Medical Times and Gazette, May 24, 1879. 



SOLE AUTHORISED MAKERS, 



KROHNE & SESEMANN, 



8, DUKE STREET, MANCHESTER SQUARE, LONDON, W. 



