Julyz\, 1879] 



NATURE 



CIX 



SUBSCRIPTIONS TO NATURE 



Yearly 28J. 



Half-yearly 14s. 6d. 



Quarterly 7s. 6d. 



To the Colonies, United States, the_ Continent, and 

 all places within the Postal Union : — 



Yearly 30s. 6d. 



Half-yearly i^s. 6d. 



Quarterly Ss. 



Office : 29, Bedford Street, Strand. 



EAGLE INSURANCE COMPANY, 



79, PALL MALL. 

 For Lives only. Established i»07. 



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



Accumulated Funds .. ._ .» ... ... ». ~. .« ;£3.o83.28i 



Also a Subscribed Capital of more than ... ». Ai, 500,000 



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

 o£ tiie Company s Agents, post free. 



GEORGE HUMPHREYS, Actuary and Secretary. 



HORNE'S POMPEIAN DECORATIONS. 



ROBERT HORNE, 



HOUSE DECOKAIOR and PAPER-HANGING 



MANUFACTURER, 



41, GRACECHURCH STREET, LONDON, ,E.C. 



By Special Appointment to His Majesty t he King ef Italy. 



LIGHTNING CONDUCTORS, 



Experier ce, accumulated suice the time of Benjamin Franklin, proTet 

 eonclusiveiy that a Conductor made of Copper of adequate size i« the b»st 

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

 destructive effects of lightninii. 



NEWaLL & CO.'S 



PATENT COPPER LIGHTNING CONDUCTOR, 



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

 Willi unvarying success, is the most Reliable, most Effective, and Clieapcsl 

 Conductor ever offered to the public. . 



It is simple in its apphcanou, no insulators being required, and it costt 

 enlv one shilling per foot for the standard siie, which is safe in any storm. 

 R. 8. NEWAIiI. * CO., 130, STRAND, W.C. 



56, WATERLOO ROAD, LIVERPOOL 

 68. ANDERSTON QUAY, GLASGOW. 

 M ANtI FACTO B -V — SATESHE A.D-ON-TYNE 



CHEMICAL & PHYSICAL APPARATUS 



BOTTLES, PURE CHEMICALS, 



And every requirement for Science Classes, Private Study, or Business 



Purposes. 



Illustrated Priced Catalogues post free for six stamps. 



Carriage allowed to any sution in England or Wales, on orders of 40J. 



value and upwards, 



MOTTERSHEAD AND CO. 



7, EXCHANGE STREET, & 10, HALF MOON STREET, 

 MANCHESTER. 



L'ELEGTRICITfi 



Rovuo scloji tin.<i u© illustr6o 



Paraissaot lo 5 et le 20 do chaque moii 

 En une belle Uvraisoi% de vingt-quatre pages grand in-8o y^u? 



T6Wgraphie. — Qalvauoplastte. — MeUorologie. — Miidecioe 

 Art militaire. — Applications divorses 



^ OROAKR SPECIAL VV.* FHOORftS DB LA LUHlf^.RB 61.EGTRIQUB 



Pablication r^dig^e de^uis 1870 avec la cullahoratioDdes 

 priucip'jux vluctrieieas fraogais et etrangers. 



S«cretairea do la Rfdaction : W. dr Fonvikllb et le C** u*Arros. 



Dirooteur : E. db Clisson, 



C0MJITI0.\'S l)'ABONi\I':MENT : 

 PARIS ETD£PARTEIfi£NTS;'-°^-.;; 'J bJ^'O" POSTALEJ* j^Jl^v; »* ^J 



ETATS-UNIS 0'AII1£R1QUE.]^^'|jV* '| \ 



Prix d'una livratson : » 75 



Vn numiro ip^cimen at euvoy^ gratia mut toute demands affranchi* 



adrexiH au bureau du Journal : 



Parla, 16, rue du Croissant, Paris. 



Now ready, a Revised Edition. 



NEGRETTI & ZAMBRA'S 



ENCYCLOP.IIDIC 



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 5s. 6^.) 



Optical, Mathematical, Philosophical, Photographic, 



AND 



STANDARD METEOROLOGICAL 

 INSTRUMENTS. 



MANUFACTURED AND SOLD BY 



NEGRETTI AND ZAMBRA, 



opticians and Scientific Instrument Makers to 



TheRoyalObservatorj^ Greenwich; theAdmiralty: 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.C., & 122, REGENT STREET, W., 

 LONDON. 



W. LADD & CO., 



Scientific Instmment Manufactorers 



{By Ap^ntmtni io ike Royal Zfutiiutipn ef Great Britain)^ 



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 Vibra- 

 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. 



Illustrated Catalogue, Sixpmee, 



EUDOLPH KOBNIG, 



(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. 



DIAMONDS AND OTHER PRECIOUS STONES. 



In consciiuencc of the many spurious gems now being offered for ;alc, 

 Mr, Brycc-Wright is prepared to give a 



SCIENTIFIC GUARANTEED OPINION 



AS TO THE 



GENUINENESS, PURITY. AND APPROXIMATE VALUE 

 Of Stones, Mounted or Unmounted, submitted to his inspection. 



BRYCE -WRIGHT, 



Mineralogist, and Expert in Gems and Precious Stones, 



90, GREAT RUSSELL STREET, LONDON, W.C. 



