clxxx 



NATURE 



{Sept. 25, 1879 



THE TELEPHONE COMPANY, LIMITED. 



36, COLEMAN STREET, LONDON, E.G. 



TESTIMONIALS. 



145 to 149, Tottenham Court Road, London, W., lAti May, 1879 

 To the Telephone Company, Limited, 36, Coleman Street, li.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 6ur 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 i 

 system in rapid communication and recognition of the voice, must create a great demand for Telephones eve'^here. — We remain, j 

 dear Sirs, yours faithfuUy, {Sigtied) J. MAPLE & Co. 



Midland Railway Telegraph Department, Superintendent's Office, Derby, 28M April, 1879 



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

 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. 



PROFESSOR HUGHES' AUDIOMETER. 



The only perfect measurer for testing the hearing power. Vide Dr. RICHARDSON'S Report to the Royal Society,! 

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



SOLE AUTHORISED MAKERS, 



KROHNE & SESEMANN, 



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



In crown Bvo, price 3J-. (>d. 



A YEAR 



LANCASHIRE GARDEN. 



BY HENRY A. BRIGHT. 



" It is full of admirable suggestions for the practical gardener as to the choice and arrangements of his plants, but 

 it will also be read with interest in the arm-chair in town. It is the story of a year's gardening written by an 

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 •^— Tijjtes. 



MACMILLAN AND CO., LONDON. 



Now ready, 8vo, price 6s. 



A TREATISE ON THE APPLICATION OF GENERALISED CO-ORDINAT]^]S 

 TO THE KINETICS OF A MATERIAL SYSTEM. 



BY 

 H. W. WATSON, M.A., and S. H. BURBURY, M.A. 



Printed at the Clarendon Press, and Published by Macmii.lAN & Co., London, Publishers to the University. 



Oxford 



W. LADD Sc CO., 



SCIENTIFIC INSTRUMENT MANUFACTURERS 



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



II and 12, BEAK STREET, REGENT STREET, W. 



IMPROVED HOLTZ ELECTRICAL MACHINES, with 4 to 24 Plates. Immediately available in any condition of the atmosphere. 



LADD'S DYNAMO-MAGNETO MACHINE and GRAMME'S MAGNETO-ELECTRIC MACHINE for Laboratory use. 



Physical Apparatus of every Description. 

 ILLUSTRATED CATALOGUE, SIXPENCE. 



NATURAL HISTORY STORES. 



48, ESSEX STREET, STRAND, W.C. 



Students and others are invited to inspect THOMAS D. RUSSELL'S 

 Collections of British and Foreign Shells, Corals, Zoophytes, Annelids, 

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Cabinets, Geologist's Hammers, Glass Capped Boxes, Card Trays, 

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SOUND: ELEMENTARY LESSONS OI 



By Dr. W. H. STONE, Lecturer on Physics at St. Thomas's HospiU 



With numerous Illustrations. 

 " This is an excellent Uttle text-book, well adapted for students of tnl^ 

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 to do something more than cram. The student of acoustics will find it a 

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 the subject, while the musician will find in its pages information which may 

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 Mechanic, 



MACMILLAN & CO., LONDON. 



Printed by R. Clay. Sons, and Taylor, at 7 and 8, Bread Street Hill. Queen Victoria Street, in the City of London, and publLihed by 

 MACMIH.AN AND Co., at the Office, 29 and 30, Bedford Street, Covent Garden. — Thursday, September 25, 1879. 



