TRANSACTIONS OF THE SECTIONS. 



37 



For the observations with which I have constructed the barometrical curves for 

 November, 1854, at Teignmouth in Devonshire, Stonyhurst in Lancashire, Wakefield 

 in Yorkshire, and Dunino in Scotland, I am indebted to Mr. Glaisher, the able 



Orkneys 

 Dunino 

 Wakefield 



Stonyhurst ... 

 Teignmouth . . . 



Secretary of the British Meteorological Society. The curve for the Orkney Islands 

 is from observations published in the 'Philosophical Magazine.' At Wakefield and 

 Stonyhurst observations are made four times a day, at the other stations twice a day. 

 The cyclonic interpretation in this case would be — First, that the curves indicate the 

 passage of a cyclone, of which the central track lay to the southward of England. 

 This is inferred from the gradual increase of the barometric depression from the 

 Orkneys in the north to Teignmouth in the south, and depends on the fact that the 

 height of the mercurial column decreases continuously from the circumference to the 

 centre of a cyclone. ITais inference is confirmed by the observation that the wind 

 blewfrom the eastward at all the above-mentioned stations. Secondly, that the cyclone 

 was progressing to the eastward. This is derived from observing that at each 

 station the wind began at S.E. while the mercury was falling, veered to E. when 

 the mercury was lowest, and then to N.E. as the mercury rose. If the wind had 



.1^ 



NB A- E^ XSE 



« 



'\ 



i 



> 



V 



->- 



-:^ 



(A) 



Ci) 



Z^' 



veered from S.W. through W. to N.W., as it does most frequently in British storms, 

 and the barometric depressions had increased from Teignmouth towards the Orkneys, 

 the interpretations would have been, that the depression was caused by a cyclone 

 travelling eastward, of which the central track lay to the north of Scotland. In the 

 first case (A), the explanation would be that the chord (S.E., E., N.E.) passed over 

 the British islands, and the chord (S.W., W., N.W.) in the second case (B). Such 

 deductions are both obvious and satisfactory to persons whose knowledge of nautical 

 technicalities has enabled them to appreciate the demonstrations of the rotatory 



