PLATE VI. 



Reduced from Special Chart prepared at the Meteorological Office.] 



North-Westerly Type of Weather. 



Isobars are shown by black lines, with indications of the height of the barometer. 

 Wind. — Arrows flying with the wind, show direction and force, thus : — 



y = forces 5 to 7 (velocity, 28 to 40 miles per hour). 



^ = forces I to 4 (velocity, 8 to 23 miles per hour). 



Vol. I.] [To face p. 176. 



