so CHARLES ORIFFIN <k CO.'S PUBLICATIONS. 



By PROFESSORS J. H. POYNTING & J. J. THOMSOM 

 in Five Volamea. Large 8vo. Sold Separately. 



A TEXT-BOOK OF PHYSICS: 



COMPRISING 



PROPERTIES OF MATTER; SOUND; HEAT; MAONETLSM 

 AND ELECTRICITY ; AND LIOHT. 



BY 



J. H. POYNTING, J. J. THOMSON, 



BCD., 7.B.S., AND "■*•' '-^-Si 



(.-%» Fellow of lYinitv College, CamhridKe; Fellew of Trinitj College, Cambridge; Pro« 



Pr..<«Mor of Physics, BirmiiiKham of Experimental Physics in the Univ^nijtT 



University. of Cambridge. 



Introductory Volume, fully Illustrated. Second Edition, Revised. 



Price 10s. 6d. 



I>ROr»EI^TIES OF IVIATTER. 



•JOKTESTB. — Gravitation. — The Acceleration of Gravity. — Elftsticity. — Streeses an 1 

 "StrainB.— Torsi on. —Bending of Rfd<. — Spiral Springs — Collision.— CompreBsibility of 

 LlqnidB.— Pressures and Soiunis of Gases,- Thernjal Effects Acconip nying Strain.- 

 Capillarity— Suriace Tension.— Laplace'.^ Theory of C'apil anty.— i iffubion of Liquid* - 

 Oiffmlon of Gases. — Viscosity of Liquids. — Index. 



Volume II. Second Edition. Fully Illustrated. Price Ss. Hd. 



S O XJ N I>. 



OoMKNTS.— The Nature of Sound and its chief Characeristics.— The Velocity of -^ound 

 m Air and other Media.— Refiicion and Refraction of Sound.— Frequency and Pitch of 

 Kotet.- EeBonance and Forced Oscillations. —Analysis of Vilirations. — The Transverse 

 Vibrfctions of Stretched Strings or Wires —Pipes and other Air Cavities.— Bodi.—Platei. 

 —Membranes.— Vibrations maintained by Heat— Sensitive Flan e« and Jeu.— Mnsioa) 

 Sind.. — The Superposition of Waves. - Index, 



"The work . . . maybe recommended to anyone desirous of possessing au east 

 oy-TO-DATE Stakdard Tkeatise on Acoustics." — Lxleraiurt. 



" Very clearly written. . . . The names of the authors are a guarantee of the 

 eoiBVTiFic ACCURACY and up-to-date characteb of the work "— EJucational Timet. 



In large 8vo, with Bibliography, Illustrations in the Text, and seven 

 Lithographed Plates. 12s. 6d. 



THE MEAN DENSITY OF THE EARTH: 



A.n Essay to which the Adams Prize was adjudg-ed in 1893 in 

 the University of Cambridge. 



BY 



J. H. POYNTING, Sc.D., F.R.S., 



[^te Fellow of Trinity College, Cambridge ; Professor of Physics, 

 Birmingham University. 



" \\\ locount of thto iubiect cannot faU to be of easAT and asFiBAL iktikist to the »cient!fie 

 mind. ii»peciallT li thl» the case when the accoant is given by one who has eontritmted so 

 considerably at nai Prof. Poynting to our present state of knowledge with respect to a very 

 diffioiill giibiect. . . . Remarkably ha« Newton's estimate b«en verified bjr Prof. Poynting.'.— 

 Athenanm. 



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