Mr. W. Brown on the Oscillations of the Barometer. 271 



sible, I have in the first place given a chart with the names and 

 localities marked upon it (Plate IV.), and the subsequent ones 

 merely contain the localities marked by dots, and set off in their 

 several places from the chart, so that by reference to it they 

 may easily be found. The arrow representing the direction 

 of the wind at Christiania, placed in the north-east corner, is of 

 course out of its relative position. I have endeavoured to re- 

 present the force of the wind, as given in nautical language, 

 by figures placed at the feet of the arrows : — being a calm, 

 1 and 2 light airs or winds, 3 moderate, 4 brisk breeze, 5 

 strong breeze, 6 a gale or stormy, 7 hard gale ; v is variable : 

 the veering of the wind backwards and forwards between 

 points is represented by two arrows from these points, and a 

 change of the wind in the latter part of the day, or night, by a 

 line crossing the foot of the arrow showing its direction. A 

 change in the force also is marked in the same way, by a line 

 underneath the figure. The direction of the wind at Paris 

 and Christiania is taken from the meteorological registers of 

 those places ; and I have also occasionally introduced arrows 

 showing its direction as noted in the registers of other places, 

 but not without caution, as I am more disposed to rely on the 

 mercantile reports, than on observations simply made by 

 noting the direction of one particular vane generally only once 

 in the day. It may also be remarked, that though the varia- 

 tions given in the firstcolumnof each dayare those which have 

 taken place during the previous night, they may yet be generally 

 considered as caused by the wind indicated by the diagrams 

 for that day, because the wind in the morning is usually that 

 of the preceding night, and when a change occurs during the 

 day it is marked as before stated *. 



Names of Places. 



Orkneys .. 

 Glasgow .. 



Belfast 



Armagh . . 



Shields 



Cork 



Bristol 



Plymouth 

 London .. 



Paris 



Christiania 



-•02 



+•03 

 -•07 



-•06 



+•12 

 +•01 



+-o; 



-•08 

 -11 



-•08 

 +•35 



+•02 

 -•01 

 -09 

 -•06 

 •00 

 -17 

 -•05 

 -•07 

 -•03 

 -•10 

 +•07 



-•06 



-•02 

 -•06 



-•04 



-02 

 -•06 



-•09 

 -05 



-•08 

 -•09 



-•07 

 +•17 



-•02 

 -•01 

 -02 



+•04 

 -•06 

 -•09 

 -•07 

 -12 

 -•10 

 -•07 

 +•07 



+•02 



•00 

 •00 



-•04 



+•08 

 +•08 



+•11 

 +•05 



+•04 

 +•07 



-•07 

 +•09 



• The shipping reports however very frequently do not state the time 

 of the clay the report refers to, when it is extremely probable the wind did 

 not continue in the same direction the whole of the day; so as to occasion 

 in some cases apparent discrepancies in the direction of the wind ; but 

 they may generally be removed by reference to some other report from a 

 neighbouring locality where a change in the direction of the wind is noted. 



