lo SCIENCE PROGRESS 



could spread out over the flat country between the town and 

 the sea. The evidence all seems to show that the suddenness 

 of the flood was not due to a climax in the rate at which the 

 rain fell, but rather to the breaking-down of various dams 

 that had been formed by drifting debris, which were holding 

 up a great accumulation of water on the western outskirts of 

 the town. Some damage was, however, done along the course 

 of every brook within the area of heavy rain and even in 

 the open fields on the hilltops, while Horncastle, which is on 

 the opposite side of the watershed, suffered severely. The 

 storm was an interesting one from the purely meteorological 

 point of view. A large area of light variable breezes extended 

 over most of Europe on the morning of May 28, and consider- 

 able heating of the air occurred on the Continent, the tempera- 

 ture rising to 94° F. at Clermont-Ferrand and 86° F. at Lyons. 

 A depression approached the English Channel from a southerly 

 direction in the course of the day, and during the following 

 night the heated air over France penetrated to the south of 

 England, causing an exceptionally warm and muggy night. 

 The southerly breezes advanced northwards during the following 

 morning, converging upon Lincolnshire by early afternoon. 

 North of the Humber there was a relatively cold wind blowing 

 in from the North Sea, the contrast of temperature amounting 

 to nearly 20° F. The warmer of the two currents appears to 

 have ascended over the colder, and being very damp the 

 dynamical cooling gave rise to exceptionally heavy rain and 

 severe thunder and lightning. Thunderstorms occurred in 

 many parts of the Midlands and Northern England, but the 

 storm over the Wolds was the most severe. At its height it 

 covered an area measuring fully 60 miles from south to north, 

 and was accompanied by funnel-shaped clouds in some places, 

 which, however, do not appear to have reached the ground 

 so as to form veritable tornado clouds. Violent squalls 

 occurred south of the centre, but in the devastated area there 

 was little wind near the ground. A southerly wind was not 

 established near the ground in Lincolnshire until some hours 

 after the rain had ceased. The evidence strongly supports the 

 theory that the whole phenomenon was due to the passage 

 of the one wind over the other, accompanied by much convec- 

 tional ascent of moist air and consequent precipitation. 



PHYSICAL CHEMISTRY. By W. E. Garner. M.Sc, University 

 College, London. 



The Lewis-Langmnir Theory of Valency. — ^The structure which 

 is ascribed to nitrogen, carbon monoxide, nitrous oxide, and 

 carbon dioxide by Langmuir has received support recently from 

 several directions. The nitrogen molecule on this theory 



