ON SEISMOLOGIGAL INVESTIGATIONS. 247 



curve, with centre on the earth's equator. Is this an old scar representing the detach- 

 ment of the moon from the earth ? The suggestion that the moon came from the 

 Pacific has been made at various times, and the occurrence of many epicentres round 

 the shores of the Pacific lent some support to the idea. Previously, however, there 

 was nothing very definite about the arrangement when we consider earthquakes in 

 general. But the deep focus earthquakes offer a more definite suggestion. Sir James 

 Jeans has kindly offered to re-examine the theoretical possibilities in this connection. 



Some Recent Shocks. 



There was a considerable earthquake near New Zealand, ' the worst since 1855,' 

 on 1929 June 16d. 22h. 47m. 10s., followed by another on 1929 June 27d. 13h. 47m. Os. ; 

 a provisional estimate of the epicentre of the first a.s 43° N. 173° E. was sent to The. 

 Times on June 18. Fifteen deaths occurred as a result of the first shock, a heavy death 

 roll for Wellington, which has lost only seven lives in all the other earthquakes since 

 1848. According to The Times correspondent, ' Westport was like a town that had 

 been bombarded, and in Greymouth not a building has escaped.' 



On the same day as the second N.Z. shock there was an earthquake in South 

 Georgia. A rough estimate of the epicentre as near the South Orkneys was sent to 

 The Times on June 28, but the corrected estimate came in a letter from Lt.-Comm. 

 J. M. Chaplin, E.N., dated 1929, Sept. 5, from Grytviken, S. Georgia, kindly com- 

 mumcated to us by the Secretary of the ' Discovery ' Committee as follows, in 

 accordance with a suggestion made by the Hydrographer (Admiral Douglas) : 



' On [1929] June the 27th, at XII-51-30 G.M.T., a violent earth tremor was felt 

 lasting three minutes and of such intensity as to make lamps swing and glass objects 

 on the laboratory shelves to rattle violently ; this is the only earthquake which had 

 ever been felt here as far as can be ascertained, up to that time, although of course 

 further south in the [S.] Shetlands they are quite common. A further shock at about 

 2 a.m. on the 26th July was noticed in the whaling station. This, however, did not 

 disturb anyone, and was not recorded in my establishment.' 



The incident led to a correspondence on the possibility of establishing a seismograph 

 in connection with the ' Discovery ' expedition, on S. Georgia or the Falkland Islands, 

 and to a visit to Oxford (on 1930 Feb. 18) by Mr. D. Dilwyn John, one of the officers 

 of the expedition, for full consideration of the matter. But it was decided that, 

 though information from that neighbourhood would be of great value, the conditions 

 did not allow of the proper care of a seismograph. 



There was a slight earthquake shock in England on 1929 July 2d. 20h. 30m., felt 

 in Gloucester and the Forest of Dean, but no damage was done. The following note 

 by Mr. R. J. R. Ward, of Denmead, Kettering Road, Northampton, was kindly sent 

 by the B.B.C. to the Meteorological Office, and forwarded by the Superintendent of 

 the Kew Observatory : — • 



' Tuesday, July 2, between 9.15 and 9.35, during Sir Walford Davies' talk and 

 very nearly towards the end of same (by the way, I was switched on to London direct) 

 the set took on a most awful rumbling sound, entirely blocking out any speech or 

 music that was on at the time. It lasted fully 20-30 seconds, and I was just going 

 to turn off, thinking it might have caught an electrical discharge, as it was very 

 thundery round about, when the speech or music was resumed in the normal. I 

 took no more notice until I heard next evening of earthquake shocks from Gloucester 

 region at the exact time.' 



Dr. Whipple adds that ' the time fits in quite nicely.' 



On 1929 Nov. 18d. 20h. 31m. 40s. there was a shock near Newfoundland which 

 broke a number of cables. As yet the epicentre is somewhat uncertain ; Strasbourg 

 gave 46° N. 54° W. ; a preliminary determination at Oxford assigned the position 

 47°-5 N. 58°-0 W., agreeing with that of the U.S. Coast and Geod. Survey ; but a 

 letter from Ottawa dated Jan. 11, 1930, gives 43°-5 N. 57°-3W., and cables were broken 

 a good deal further south still (as well as further north). The Telegraph Construction 

 and Maintenance Company have very kindly supplied information ; and Commander 

 Robinson, R.N., of the Eastern Telegraph Company, says that ' the most serious 

 damage occurred in an area between about latitudes 44° N. and 45° N. and longitudes 

 55° W. and 57° W., and that in an area further south round 40° N. and 53°-5 W. a 

 cable was broken about Nov. 19d. lOh.' There was, however, no aftershock at this 

 time, and though there were aftershocks at Nov. 18d. 23h. and 19d. 2h. they were very 



