1883.] 



On a Series of Barometrical Disturbances. 



145 



turbance, as a shallow hollow, can be traced in a few of the curves, 

 after which nothing can be distinguished. 



By a comparison of the time intervals between the first and third, 

 the third and fifth, and the fifth and seventh disturbances, and 

 assuming (which the facts seem to justify) that the velocity of the 

 wave has remained unchanged in its passage from east to west, it 

 would appear that the first well-defined rise in the first of the series 

 corresponds to the rises which are prominent in those succeeding it. 

 And the same conclusion has been drawn from an examination of the 

 second and fourth compared with the fourth and sixth of the 

 series. 



Adopting these conclusions, the times of the successive passages of 

 the initial rise have been measured from the curves, suitable 

 allowance having been made where the rise was difficult to trace, or 

 as sometimes happened, a hollow appeared corresponding in position 

 with the hollows in the- earlier form of the disturbances. There is, of 

 course, some doubt attaching to these measurements, but their general 

 consistency seems, to indicate that they may be accepted as fairly 

 representing the facts under discussion.. 



The following- table gives the results, of these estimates of the 

 times at which the successive waves passed the- several stations, 

 reckoned from midnight of the 26th August, in Greenwich mean 

 time. 



Table II. 



Place. 





Times of 



passage 



of wave. 







I. 



II. 



in. 



IV". 



Y. 



VI. 



VII. 





h- in. 



h. m. 



h. m. 



h m. 



h. m. 



h. m. 



h. m. 





55 



25 10 



: 55 10 



1 61 30 











13 55 



26 30 



50 50 



! 62 5 



87 55 



96 10 



124 45 





13 50 



. 26 55 



50 30 



; 62 40 











13 30 



26 45 



50 40 



62 15 



87 45 



96 20 



124 30 



Falmouth 



13 25 



; 27 



50 25 



62 15 





97 45 



124 30 





13 30 



27 



50 35 



62 20 



87 35 



97 30 







13 20 



i 26 50 



50 25 



62 25 



87 40 



97 30 



124 5 



Aberdeen .......... 



13 20 



27 5 



I 50 30 



62 30 



87 20 



98 30 







13 15 



27 15 



50 15 



62 30 





98 



124 5 





13 15 



27 15 















13 15 



27 30 



50 



62. 50 











12 35 



27 45 



50 



62 55 



86 45 



98 40 





St. Petersburg!! . . . 



11 15 



. 28 40 



48 30 



63 50 



84 40* 







From these figures are deduced the intervals between the successive 

 passages of the waves from east to west, and from west to east, 



