140 



Mr. R. H. Scott. 



[Dec. 13, 



east longitude). The continuance of the shocks is given at from 

 4 p.m. on the 26th to daybreak on the 27th, corresponding to the 

 interval from 9 a.m. to 10 p.m. on the 26th, Greenwich time ; but they 

 probably continued for a longer period. No precise statement as to 

 the moment of occurrence of any particular explosion or shock has 

 as yet been printed. 



Two letters have been received at the Meteorological Office from the 

 Board of Trade, one from Her Majesty's Consul at Batavia, and the 

 other an extract from the log of the Dutch steam ship " Governor- 

 General Loudon," which ship was in Sunda Straits at the time of the 

 eruption, having called at Anjer the day before it took place, and 

 again after the place had been swept by the earthquake sea-wave. 

 Neither of these accounts contains- any precise statement as to time of 

 any particular phenomenon. 



The facts which I have to bring to the notice of the Society are the 

 indications of successive disturbances of the barometer occurring also 

 at the end of August, at regular intervals and at every observatory in 

 Europe.. 



I shall distinguish the four disturbances shown on the engraving 

 by Roman numerals. Greenwich time is used.. 



I. At about 11 hi. a.m. on the 27th,. a sudden increase of pressure, 

 followed by a decrease, appeared at St. Peters-burg, and a similar 

 phenomenon was- noticed at Valencia Island, and at Coimbra in 

 Portugal, as well as at all the intermediate observatories over Europe 

 from which we have been able to obtain tracings of barograms. 



The character- o£ the disturbance was not strictly identical, for at 

 the western stations the rise of the barometer- was more marked than 

 at the eastern. The general appearance of the barograms at adjacent 

 stations- is strikingly similar.. It is, however, difficult to select any 

 peculiarly remarkable phase of the- disturbance so as to recognise it 

 and record the time of its- occurrence at each observatory. 



This movement (I) was propagated from east to west at a very 

 high velocity, for the recovery of pressure from the first decrease 

 occurred at St. Petersburg at noon, and at Valencia at 2 h. 25 m. p.m. 

 on the same day,, thus taking only two hours and twenty-five 

 minutes to traverse the distance of 1,315 miles between the two 

 observatories. 



II. A somewhat similar disturbance- appeared on the 28th, but was 

 propagated from west to east, reaching Valencia at 3h. 20 m. a.m., 

 and St. Petersburg at 5 h. 15 m. A.M., and thus- requiring only one 

 hour and fifty-five minutes for its passage. The same uncertainty as 

 to identification of the phase exists in this case as in the preceding. 

 In all cases, however, the most marked phase of the- phenomenon has 

 been noted. 



III. A disturbance travelling in the same general direction as No. 1. 



