272 REPORTS ON THE STATE OF SCIENCE, ETC. 



practically drops out, leaving only the ScPcS. This work was done on cards, and it was 

 easy to remove the cards referring to SoPcS. Those left showed something much later 

 than S ; but it seems better to say no more until the discussion is complete. 



New Stations. 



The number of observatories which send readings for inclusion in the Intematioual 

 Seismological Summary continues to increase. In May 1923 a list of 165 was 

 published, and in November 1925 a list of forty-six more. Seven more are to be added 

 to date, making 218 in all. Some of these have dropped out of action, and some send 

 only rarely, but even after these deductions the list is a long one. Among stations 

 recently established, a special welcome is due to Sucre in Bolivia (19'0^S., 65-3^ W.), 

 which collaborates with La Paz (16-5'^ S., 68-1° W.). Many shocks in South America 

 are too slight to reach many observatories, and a pair of stations not very far apart 

 is very useful on such occasions. An even closer pair is formed by La Plata (34-9° S., 

 57-9<^W.), and Chacarita (34-6° S., 68-5'" W.). Readings from La Plata for the later 

 months of 1922 were received just in time for inclusion in the number of the Summary 

 before it was passed for press, and it is hoped that they will henceforward be available ; 

 but there is still a tendency to delay communication of the information. The 

 Summary for October-December 1922 is being passed for press at the time of writing 

 (July 1926), and is thus in arrear by three years and five months ; an interval which 

 was much larger just after the War, but has been steadily reduced at the rate of about 

 six months per year. Its limiting value, however, will depend upon the most backward 

 stations, for it adds greatly to the labour of producing the Summary when information 

 is received at the last moment. Hence observatories are earnestly requested to send 

 their readings as soon as possible. 



Time Determinations. 



Before and during the War the time-determinations at many of the outlying 

 stations were undoubtedly faulty, which complicated the process of interpreting the 

 readings. A great improvement in this respect has followed on the introduction of 

 wireless time-signals, though we in Europe perhaps overestimate the facility of getting 

 accurate time in this way. For instance, the table of readings for Dehra Dun for 1925 

 is accompanied by the note : ' The time is expressed in Indian Standard Time, which 

 is five hours thirty minutes east. It is liable to error as great as thirty seconds.' 



If this is the state of things at the headquarters of geodesy in India, there must be 

 even greater uncertainty at more outlying stations. Moreover, even where wireless 

 signals are available, so that the seconds may be trusted, the minutes or hours may 

 go wrong. Indeed, it seems possible that confidence in the seconds has begotten a 

 little carelessness about the minutes. Perhaps the mistakes are made in applying 

 the longitude, though in these days of standard time this ought not to upset the 

 minutes. 



Visit to Comrie. 



As above mentioned, a visit was paid in August 1925 to Comrie, in Perthshire, 

 where sixty-eight earthquake shocks were recorded between 1788-1804, and over 

 300 shocks in the eleven years 1839-49. There followed, however, fifteen blank 

 years, and only fifteen shocks in the years 18G4-1898, with a couple more in 1020. 

 The village seems to regret the cessation. As the local guide-book puts it : ' The 

 district misses the gratuitous advertisement which these shocks gave. Thus it has 

 been found advisable to bring the merits of the place before the public in ordinary 

 up-to-date advertising style.' 



Interest in earthquakes is, however, still maintained, and has been rewarded since 

 my visit by a couple of renewed shocks (1926, February 22 and 23). There was, 

 however, little of importance to be gathered on the spot. The ' earthquake house ' 

 where experiments were made is still in existence, and by the courtesy of the present 

 owner of the property (Mr. Drummond) I was allowed to see it. There is now no 

 trace of its former occupation — it might be an ordinary summer-house. Objects 

 like small ninepins of various cross-sections were set up on the floor ; the observations 

 consisted in noting which of them fell and what was the direction of fall. Tradition 

 preserves the memory of a complete fall and scattering of the pins which could be 

 associated with nothing seismological, and was ultimately traced to a raid by boys. 



