350 Gn Rock*, $c. t from the Kumkoram-Hiiiiniiiittx. 



pointed oat and adopted. A correction is also calculated and appli 

 for another disturbance which still remains. 



4. The chief experiment* is on interference phenomena, somewl 

 analogous to Newton's rings, bj transmission. The resultant 

 depends upon about 200 electrometer readings. 



5. The experiments conclude with two examples^ of modificatic 

 of the secondary which produce no reflexion. These consisted 

 spectively of thinner wires nearer together, and of thicker wi 

 further apart, than the normal spacing. In each case the capacity i 

 practically unaltered by the change in the wires ; hence, as anticij 

 from the theory, no reflexion occurred. 



6. The systematic comparison of theory and experiment, 

 near the end of the paper, does not exhibit an absolute quantit 

 agreement. Nevertheless, the two are so far concordant in all 

 general features as to be mutually confirmatory, and were appi 

 by Professor Hertz || as close approximations. 



IV. " On Rocks and Minerals collected by Mr. W. M. Com 

 in the Karakoram-Himalayas." By T. G. BONNET, 

 F.R.S., Professor of Geology in University College, Londc 

 and Miss C. A. RAISIN, B.Sc. Received February 15, 18J 



(Abstract.) 



During his journey in the Karakoram-Himalayas, Mr. W. M. 

 way collected more than 300 specimens of rocks and mine 

 generally rather small, which have been examined by the authc 

 They give a general summary of the results obtained, together 

 the details of chief interest. 



Among the rocks are numerous specimens of granite and gne 

 (the latter frequently pressure-modified granites), diorites, and hoi 

 blende schists, crystalline limestones and dolomites, calc-i 

 micaceous, and other schists, ordinary limestones, sandstones 

 some conglomerates, argillites, slates, and phyllites, as well as 

 peculiar mottled felstones, probably devitrified acid lavas, from 

 locality (Golden Throne Peak). Of these rocks, the most int 

 are a dark green serpentine, very like a variety common in the Alj 

 .some hornblendites, piedmontite-schists, schists with a seconc 

 brown mica, the crystals in one case being quite a quarter of an ii 

 in diameter; a partially altered argillaceous rock, in which si 



* Expt. V, arts. 4248. 



t Curve E, fig. 10. 



I Expts. VIII and IX, arts. 6162. 



Arts. 6377. 



|] Under whose able guidance the work was carried out in Bonn, 1892-03. 



