200 Report of the Meteorological Committee. . [Jan. 20, 



of the centre of the disturbance. The Office has appealed to the owners 

 of all British vessels at sea in the Atlantic during the month in question, 

 and has met with a very satisfactory response, having received no less 

 than 280 logs, a larger number than has ever before been available for 

 such an inquiry. 



The charge of the issue of storm- warnings &c. has necessarily been 

 wholly confided by the Committee to the Director of the Office, who, in 

 reply to our inquiry how far the principles by which he is guided admit 

 of being formulated, has furnished us with the following remarks : — 



" The chief of these principles, which are only announced with very 

 great diffidence, as being liable to material modification with the growth 

 of experience, are as follows : — 



" I. The Lata hioivn as Buys Ballots, which is simply a general ap- 

 plication of the Law of Storms announced by Bedfield and 

 Eeid. 



" The intelligent application of this principle to wind motion, 

 even on the most extensive scale, has been the chief point in which 

 modern meteorology offers a contrast to prior investigations into 

 the science. 



" This law gives not only the direction of the wind, but also its 

 force, which is measured with more or less accuracy by means of 

 gradients. That it is not absolutely true in all cases and condi- 

 tions is more than probable, although precise statements on this 

 subject are not accessible as yet. 



" As regards Direction, the indraught of wind across the isobars 

 in front of an advancing storm is indisputable, as is the effect of 

 land in modifying the motion of the air. 



" As regards Force, it is clear that the same gradient does not ac- 

 company the same force of wind from all points. A further proof 

 of this statement is to be found in a fact which has been elicited 

 by the investigations into the meteorology of the sea, that for the 

 same force of wind the gradient is less in the S.E. than in the 

 N.E. Trade. 

 11 II. The mutual Relation of areas of loiu and of high Barometrical 

 Pressure, the former being to a great extent regulated as to 

 their motion by the latter, and skirting them on their western, 

 northern, and eastern side, at least ; so that when we have an area 

 of high pressure situated over a portion of these islands, we can 

 form a good idea of the probable direction of motion of cyclones 

 in our neighbourhood — e. g., the existence of an anticyclone over 

 Ireland is accompanied by the advance of cyclonic disturbances 

 southwards over the Baltic or North Sea, causing northerly gales 

 on the east coast of England. 



" The above principle is manifestly incomplete, inasmuch as it 

 takes no account of the rarity of any westward motion in the cyclones. 



