26o REPORTS ON THE STATE OF SCIENCE, ETC. 



1914. It was transferred to Oxford in exchange for No. 32 (see report, 

 1927). 



Early in 193 1 a letter was received from Dr. H. Spencer-Jones, H.M. 

 Astronomer at the Cape, in which he expressed the opinion that the 

 seismographic records at the Royal Observatory were of little value. Owing 

 to the instability of the zero of the seismographs it had been necessary to keep 

 the sensitivity very low. The Committee agreed with Dr. Jones's view that 

 the instrument should be moved to another site, but considered it important 

 that it should be kept in South Africa. Subsequently Dr. Grindley volun- 

 teered to erect the seismograph at the Cape Town University, which is 

 several miles from the Observatory. In the basement of the University 

 he found both microseisms and changes in zero relatively small. Prof. 

 Alexander Brown, head of the Department of Applied Mathematics, has 

 kindly undertaken to continue the observations until the end of the year 

 1932. If the results are satisfactory the seismograph will remain in opera- 

 tion at the University. 



Mr. Shaw has supplied a Milne-Shaw seismograph to the Department 

 of Geology, Liverpool University, where regular observations are to be 

 commenced in September. Two Milne-Shaw seismographs are being 

 despatched to the Department of Geology, University of Vermont. 



Mr. Shaw has also made during the year a seismograph adapted for 

 public exhibition. This instrument is set up on the third floor of the Store 

 of Messrs. Selfridge & Co. Ltd. in London, and attracts much attention. 

 On several occasions the public have watched whilst severe earthquakes 

 were being recorded. The records are on smoked paper on an open scale. 

 It is found that the pendulum, which is supported by one of the main 

 stanchions of the building, is affected neither by traffic in the streets nor 

 by the movement of people in the Store. 



British Earthquakes. 



In 1932, January 10, at 4.15, a slight earthshake was felt at two villages, 

 Aylesham and Nonington, near Canterbury. Three distinct rumblings 

 were heard below ground in the Snowdown mine, dust flew and hurt men's 

 eyes, mice began to squeak, and the miners ran from the coal face. It is 

 presumed that the earthshake was due to some collapse of old workings in 

 the mine. 



A small earthquake, which was felt in Yorkshire in 1932, May 25, at 22 h. 

 G.M.T., was recorded by the seismographs at Stonyhurst and Durham, 

 though not by those at Bidston and West Bromwich. The epicentre 

 appears to have been in the Hope Valley near Sheffield. 



Small disturbances not recorded by seismographs were reported by news- 

 papers as occurring on the following dates : 



1931, Dec. 18, Nottingham. 1932, March 17, Oban. 



1932, Jan. 13, South Carnarvonshire. 1932, July 7, Shrewsbury. 

 1932, Jan. 16, Manchester. 



Deep Focus Earthquakes. 

 The question of the depth of focus of earthquakes continues to occupy 

 the attention of seismologists. As was mentioned in the last report of the 

 Committee, records of the earthquake which occurred on February 20, 

 193 1, were collected at Kew Observatory. A discussion of the records by 

 Mr. F. J. Scrase will be published shortly. The focus of this earthquake, 

 the epicentre of which was in Siberia near the Sea of Japan, was at a depth of 

 360 km. A good example of an earthquake with deep focus is dealt with 

 in one of the recent issues of the International Seismological Summary. 



