160 Intelligence and Miscellaneous Articles. 



Green, Damery, Micklewood, Daniel's Wood, etc. At Charfield 

 their general run is north-north-west and south-south-east, and the 

 upper band is associated with a bed of calcareous ash. The ash 

 contains lapilli, felspar-crystals, quartz-grains, small shaly patches, 

 and fossils, cemented by calcareous matter. The fossils, determined 

 by Mr. Cowper Reed, probably indicate the Wenlock age of the rock. 

 The associated trap would thus seem to be interbedded — a conclusion 

 strengthened by its uneven surface and highly amygdaloidal 

 character. 



At Daniel's Wood the higher bed of trap is overlain by limestones 

 which contain Wenlock fossils, and underlain by rocks with Upper 

 Llandovery fossils. The dip of the rocks appears to indicate the 

 existence of an anticline. The rocks underlying the trap-band of 

 Damery Quarry are not seen, but above the trap are rocks bearing 

 Upper Llandovery fossils. This trap occupies a large area near 

 Woodford Farm. The same band of trap at Middle Mill underlies 

 an ash-bed in which fossils of Upper Llandovery age have been 

 found. The rocks, as a whole, follow the north-eastern and northern 

 boundaries of the Bristol Coalfield. 



The microscopic examination of the lower igneous rock shows 

 that it is a basaltic audesite containing plagioclase (acid andesine or 

 oligoclase), pseudomorphs after enstatite, with chloritic and iron- 

 oxide patches. The higher bed sometimes contains fresh augite, 

 and both bands frequently contain rounded grains of quartz. In 

 other examples the felspars appear in three forms, with augite and 

 enstatite, and the rock ranges from an andesite to a porphyritic 

 basalt. The quartz-grains present appear to be xenoliths. The 

 silica-percentage of the rocks on a moisture-free basis varies from 

 61 to 67, while the specific gravities are from 2*74 to 2*99. 



XI. Intelligence and Miscellaneous Articles. 



To the Editors of the Philosophical Magazine. 



Battersea Polytechnic, London, S.W.. 

 Gentlemen, — 



IN the June number of the Phil. Mag. there appears a letter 

 from W. Rollins commenting on a paper of mine in your issue 

 for April. It appears to me to be entirely unnecessary ; as nowhere 

 in my paper have I said that he, originally, was responsible for the 

 idea that the gas escapes through the walls of a Crookes tube. If 

 he had read my paper before writing his letter he w r ould probably 

 have noticed this ; and, if we may judge from the abstract of his 

 own papers which he is good enough to give, he would perhaps 

 have found other points of interest in the paper not noticed in 

 his own. 



I am, Gentlemen, 



Tours faithfully, 



R. S. Willows, 



