Tempeeatubes and Pressures in a Block of Atmosphere 



24 KiLOMETBES (15 JIlLES) THICK OVER A TRIANGULAR PORTION OF THE BRITISH ISLES. 



Fig. 7.— From observations taken on July 27th, 1908, at Ditcham Park, Watlington, 

 Jlanchester, Crinan and Limerick. Block seen from the north-east. Isotherms are 

 shown for each 5- Absolute from 280- A. to 215" A. The space between the isotherms 

 of 270" and 275° is filled in ; for other isotherms a thickness corresponding with J^ C. 

 is covered. The beaded lines in the stratosphere are isobars for 0-2 megadyuc and O'l 

 megadyne per square centimetre respectively. The arrows on the standards face the 

 wind as determined by observations with theodolites. 



Pig. 8.— Prom observations taken on July 29th, 1903, at Watlingtou, Manchester, 

 Crinan and Limerick. Block seen from the north-east. Isotherms are shown for each 

 5 Absolute from 285° A. to 205° A. The space between the isotherms of 270'" and 273" 

 is filled m ; for other isotherms a thickness corresponding with i° C. is covered. The 

 beaded lines in the stratosphere are isobars for 200 mb. and' 100 mb. per square 

 centimetre respectively. The arrows on the standards face the wind as determined 

 by observations with theodolites. 



The reader should notice the isobar of 30-4 in. (1029 mb.) on the map in this figure 

 which crosses the coast between Spurn Head and Plamborough Head, and compare its 

 position with that of the isobar of 30-1 in. (1019 mb.) in Pig. 7 which is a little further 

 to the north. In the interval of two days a layer of cold air has spread along the 

 base ot the stratosphere from the eastward, and the pressure at the surface has become 

 "'""'—by lOmb. 



