﻿Intelligence and Miscellaneous Articles. 577 



which, in their opinion, was passed over too lightly by the author 

 of that paper. 



They further affirm, in the course of a description of the sections, 

 which are most clear and afford the best evidence : — 



(1) That the strike in both the supposed rock-groups is generally 

 similar. 



(2) That the same is true of the dips. 



(3) That very marked identity of lithological characters may be 

 found in rocks on either side of the alleged unconformity, specimens 

 occasionally being practically indistinguishable. 



(4) That in no case, which has been examined, can any valid 

 evidence be found in favour of the alleged unconformity, and that 

 iu the one which is supposed to be the most satisfactory proof of it 

 the facts are wholly opposed to this notion. 



LXIX. Intelligence and Miscellaneous Articles. 



ON THE ENERGY OF THE AMPERIAN MOLECULE. 

 To the Editors of the Philosophical Magazine. 

 Gentlemen, 

 YVTITH reference to the paper by Mr. Fawcett and myself 

 * * published in your last issue, Prof. Oliver Lodge has kindly 

 sent me the following interesting considerations. 



If temperature is due solely to translational and vibrational 

 motions of molecules, it is possible that an appreciable time may 

 be required before the sudden alteration of the rates of rotation 

 of the molecules of a piece of iron can cause an alteration in the 

 temperature of a neighbouring thermopile. It follows that, if this 

 be so, an inseparable connexion may still exist between molecular 

 spin and molecular magnetism, in spite of our negative result. 



It is true that our experiments lasted on the average from two 

 to three minutes, and in two cases for four minutes and a half, 

 without any marked temperature effect appearing ; but an exami- 

 nation of our results in the light of Dr. Lodge's suggestion does 

 certainly show that in every case (except curve /, where the tem- 

 perature was probably changing rather rapidly) there is a very 

 slight upward tendency of the curve after the first sudden bend is 

 over, which is in the direction of the effect sought ; and this ten- 

 dency is also most conspicuous in the earlier readings (p. 477), 

 where the time-interval was greatest. 



I confess that it had not occurred to me as possible that several 

 minutes might elapse before an alteration in the rotations of a set 

 of molecules could make itself felt in their translational velocities, 

 and for molecules consisting of more than one atom this still 

 seems to me very unlikely ; but if the rotations dealt with are 

 those of single atoms spinning about their own centres, between 

 which it is perhaps not unreasonable to assume the absence of any 

 marked tangential forces during collision [and I take this to be the 

 case contemplated by Dr. Lodge], there seems to be no reason why 

 Phil. Mag. S 5. Vol. 38. No. 235. Dec. 1894. 2 R 



