Ixii 



NATURE 



\yune 19, 1879 



MEDALS -PHILADELPHIA, 1876. MEDALS— PARIS, 1878 



8ETH THOMAS CLOCK COMPANY, 



NEW YORK, CHICAGO, SAN FRANCISCO, and LONDON. 



MANUFACTURERS OF 



CALENDARfCLOCKS, REGULATORS for ASTRONOMICAL 



AND SCIENTIFIC PURPOSES, 



TURRET CLOCKS FOR LARGE BUILDINGS. 



AND 



HOUSE CLOCKS OF EVERY DESCRIPTION. 



Prices and Particulars from any respectable Watchmaker, or Wholesale and Jor Shipment from 



R. M. MARPLES (SOLE AGENT), 

 16, WORSHIP STREET, LONDON, E.C. 



THE TELEPHONE COMPANY, LIMITED, 



36, COLEMAN STREET, LONDON, E.C. 



TESTIMONIALS. 



I4S to 149, Tottenham Court Road, London, W., \i,th May, 1879 

 7(7 Mi" Telephone Company, Limited, 36, Coleman Street, E.C. 



Dear Sirs, — You will be pleased to hear that the forty Telephones you supplied answer admirably, and are of great con- 

 venience, communicating as they do in some cases with our workshops a mile away. 



The simplicity and ease with which they work, being able to be used by any one, and the great advantage over the Telegraph 

 system in rapid communication and recognition of the voice, must create a great demand for Telephones everywhere. — We remain, 

 dear Sirs, yours faithfully, (Signed) J. MAPLE & Co. 



Midland Railway Telegraph Department, Superintendent's Office, Derby, 7.%th April, 1879 

 Dear Sirs, — In reply to your inquiry of the 25th inst., I have the pleasure to inform you that the Telephones which have 



been erected on the Midland Railway are working very satisfactorily. — Yours faithfully, (Signed) W. LANGDON 



The Telephone Company, 36, Coleman Street, London, E. C. 



Application for Price Lists or further information to be made to the Manager. 



W. L A D D & CO.. 



ScientiJSc Instniment Manofactorers 



i.By Appointment to the Royal Institution of 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 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. 



Illustrated Catalogue, Sixpence. 



NOV/ READY, 

 SECOND EDITION, 



GRIFFIN'S 



CHEMICAL HANDICRAFT. 



PRICE ts. 7d. 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 Appaiatus. 



JOHN J. GRIFFIN and SON.S, 22, GARRICK STREET, 



LONDON, W.C. 



NEW ILLUSTRATED CATALOGUE of ELECTRIC 



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

 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 alt Descripiions/or Lecture Purposes Loaned on^. 

 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., fjr 



Fixing. 

 EDISON'S ELECTRIC PEN £i &s. 



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. 



DARTON'S 

 GUINEA ANEROID, 



With Thermometer. Dial is dlvidei off 

 looths of an inch. Accurate and sensiti' 

 Kach instrument tested in presence of ci 

 tomer, if required. Price lis. The sam< 

 mounted in Carved Oak Frame, various pat- 

 terns, 42J. and 63J. 



Illustrations and Prices on Application. 



F. DARTON & CO., Makers, 



45, ST. JOHN STREET, E.C, 



WORKS-ST. JOHN'S LANE. 



