slvi 



PEOCEEDINGS, 



Second Confeeence. 



The princiijal subjects brought before the second conference 

 were as follows : — Meteorological Photography, Earth-Tremors, 

 the Pollution of Air in Towns, the Erosion of the Sea Coast, 

 Underground Waters, Erratic Blocks, Geological Photographs, 

 the Teaching of Geography in Schools, and the Ethnographical 

 Survey of Great Britain. 



Meteor olocjical Photography . — The work of this Committee has 

 already been brought before our Society by its Secretary, Mr. A. "VV. 

 Clayden, in a lecture delivered at St. Albans in 1891, to the 

 report of which in our 'Transactions' (Vol. YI, p, 162) reference 

 should be made. At this Conference Mr. Clayden stated that 

 a sufficient number of photographs of clouds had now been received, 

 but he would be grateful for photographs of lightning showing 

 anything abnormal ; and also for photographs showing the results 

 of whirlwinds or other exceptional occurrences. 



Earth-Tremors. — We are scarcely likely to assist this Committee, 

 the investigation of earth-tremors requiring an instrument costing 

 at least £60. That best suited for the pui'pose, and adopted by 

 this Committee, is the bifilar pendulum invented by Mr. Horace 

 Darwin, who exhibited one to the Conference and explained its 

 construction and use. It is not affected by certain rapid, com- 

 plicated movements which take place during an earthquake, or 

 by the slight tremors caused by passing carts or trains. The 

 movements which it will measure are such as would make a factory 

 chimney or a vertical post fixed in the ground lean over on one 

 side. Extremely small movements of this kind can be measiu-ed 

 by it and recorded on photographically-prepared paper. An account 

 of the instrument was given in 'Nature' of 12th July, 1894, and 

 also in the 'Report of the British Association' for 1893, p. 291. 



Mr. G. J. Symons, Chairman of the Committee, stated that 

 pulsations recorded by one of these instruments in a coal-mine at 

 Newcastle- on-Tyne had been traced to the gradual settlement of 

 the ground in consequence of the removal of the coal, and to the 

 beating of the sea-waves on the coast. On one occasion the pulsations 

 shown were found to have been produced by an earthquake in 

 Greece. The Committee wished to have several of these instru- 

 ments established in different parts of the British Isles, in order to 

 make sure that not merely local phenomena were being recorded, but 

 the great general phenomena of the earth's crust, such as changes 

 going on in connection with faults in geological strata, and records 

 of the alterations in the earth's crust caused by tidal waves. 



Pollution of Air in Towns. — For the last three or four years 

 Dr. G. H. Bailey has been examining the air of towns in order 

 to ascertain the extent of its pollution, and he gave an account 

 of his investigations in Manchester. It was a question, he said, 

 of much practical importance, for it had been found that the 

 death-rate was highest when the air was most polluted. The 

 amount of sulphur-compounds present in the air was a measure 

 of the extent of its pollution. The amount of sunlight in towns 



