40 



Life and Lettertt of Francin Galton 



the black areas of low pressure on the baromet<>r charts corresponding to a 

 whole series of counter-clockwise runninp; arrows on the wind charts; and 

 the second half of the month marked a series of anticyclones — the red areas 

 of high pressure on the barometric charts corresponding to a whole series of 

 clockwise running arrows on the wind charts. About the middle of the month 

 we have the transition from black to red areas on the Imrometric charts, and 

 here sure enough ai*e two systems of arrows on the wind charts one counter- 

 clockwise and tme clockwise. Hut it is very clear that the broad band from 

 the Skelligs to Konigsl)erg, west and east, and from tSiena to Cliristiania, south 

 and north, was largely insidequate to exhibit the 'cores' of a cyclone and 



G5.Ron''$ Ee>.rlL) Ide^ of 

 /intACL{clon.e bxiA CLjclone 



SCALE lOOO MILES 



/Inticijclone 

 (dispersion) 

 Hi^h Bi>.rometer 



Cijclone 

 (indraught) 



anticyclone on the same chart. The cores of one or other or even of both lay out- 

 side the lai-ge area for which Galton was plotting simultaneous observations. 

 As I have already remarked, a single continent is scarcely sufficient for the 

 study of meteorological observations. Such is one of the jnain lessons of the 

 Met€oro</raphwa,and one doubts if it had been realised l>efore that publication. 

 Yet Galton recognised that if an observer in the northern hemisphere supposed 

 himself standing at the core of an anticyclone — i.e. a centre of high pressure — 

 and facing towards the core of a cyclone — i.e. a centre of low pressure — the 

 winds would pass from his left to his right hand. If we term the line of his 

 sight a bi-cyclonic line, Galton in his Royal Society paper of December 1862 



