President's addrej^S. cix. 



ceases, and the air sometimes gets a little warmer for a time, or 

 loses its heat at a much slower rate. The cause of this isothermal 

 layer has not yet been satisfactorily explained. The rainfall of 

 the United Kingdom for 1907 was very near the average, the 

 most striking feature in Dorset being the large fall in October, 

 when my rain gauge recorded over nine inches in 28 days, or 

 nearly a third of the year's rainfall ; but this was considerably 

 exceeded elsewhere in the county, where the average rainfall is 

 greater. September 6th— 30th was an almost dry period. An 

 unparalleled downfall of rain occurred on August 8th — 9th, 1906, 

 in Fiji, when in a thunderstorm about 41 inches of rain fell in 

 13 hours. How any vegetation or soil remained on the island I 

 cannot imagine ! A hailstorm with hailstones up to about 

 i|in. in diameter occurred at Cairo on October 21st, a rare 

 phenomenon there. The snowstorm in the early morning of 

 April 25th, 1908, was almost unprecedented, and though not so 

 bad in Dorset, in Hampshire it fell to the depth of 2ft., blocking 

 the railways and making roads impassable. It Avas emphasised 

 by the extraordinary rise in temperature on May ist, when 

 summer seemed to come upon us suddenly after a long cold 

 spring. The mean temperature for 1907 in London was close to 

 the average ; but a cold summer, with the beginning of Septem- 

 ber about 30 degrees colder than in 1906, produced the impression 

 of a very cold year. Eighty degrees was the highest temperature 

 recorded ; but the number of hours of sunshine was much above 

 the average, and the London death rate was the lowest on record. 

 The sunshine for 1907 at Weymouth was only 2 J hours below its 

 very high average of i786'6 hours. A curious observation has 

 lately been published in Japan of the tilting of the land under the 

 influence of a cyclone on two occasions, in 1904 and 1906, the 

 tilting amounting to 3^ degrees and 2*87 degrees respectively. 

 The general influence of the moon on the weather I am. not bold 

 enough to discuss, but from observations at Potsdam extending 

 over six years, it has been decided that the full moon has no 

 effect in dispersing clouds. I must confess that it has often 

 seemed to me to do this ; but this is explained by a statement 



