Intelligence and Miscellaneous Articles. 549 



were deposited in the Lithgow district, but it is doubtful if they 

 ever extended to Bathurst. There is nothing to show what happened 

 in this region during Mesozoic and early Tertiary times. The 

 Hawkesbury Sandstone (probably Triassic) may have approached 

 nearer to Bathurst than it does now. In late Tertiary times stream- 

 deposits were formed on the granitic rocks, and afterwards covered 

 with thick basaltic lava-noWs, which have since undergone much 

 denudation. 



2. 'The Geology of Matto Grosso (particularly of the region 

 drained by the Upper Paraguay).' By J. W. Evans, D.Sc, LL.B., 

 F.G.S. 



The district includes a portion of the Brazilian hill-country, and 

 also of the low-lying plains to the south-west." 



The rocks principally dealt with are unfossiliferous, and of un- 

 known age, except that they appear to be older than the Devonian, 

 They may be classified as follows : — 



5. Matto Sha'es. 



(Relations not shown.) 

 4. Bizama Sandstone. 



(Perhaps some unconformity.) 

 3. Curumba and Arara Limestones. 



(Yery marked unconformity.) 

 2. Cuyaba Slates. 



(Strong unconformity.) 

 1. Ancient crystalline rocks. 



The Devonian and later rocks are briefly described. 



3. ' Notes on the Occurrence of Mammoth-remains in the Yukon 

 District of Canada and in Alaska.' By George M. Dawson, C.M.G., 

 LL.D., E.R.S., E.G.S. 



LVI. Intelligence and Miscellaneous Articles. 



ABERRATION PROBLEMS. 

 To the Editors of the Philosophized Magazine and Journal, 



GrENTLEMEE", 



1VTQW that my paper of March 1892 on Aberration and Ether 

 ^ Motion has been published by Messrs. Kegan Paul & Co. for 

 the Royal Society (Phil. Trans.), I ask permission to state that refer- 

 ence to an experimental investigation made at Leipzig in 1889 by 

 Th. des Coudres was unwittingly omitted (Wied. Ann. vol. xxxviii. 



p- 73 )- 



It consisted in observing the mutual inductance of a pair of coils 

 when their common axis made different angles with the Earth's 

 motion through space ; the apparatus used being a kind of induction- 

 balance. So far as I reLiember it is the first electrical experiment 



