THE RELATION OF METEOROLOGY TO HORTICULTURE. 19 



to fill the enclosure to the top of the wall. Or, taking the area of Hyde 

 Park and Kensington Gardens together as 700 acres, if the same amount 

 of water had been turned into that space a wall nearly the height of the 

 Eiffel Tower, or exactly 978 feet high, would have been needed to retain it. 



A fall of one inch of rain does not appear at first sight to be much ; 

 but spread over an area of two square feet such a fall would measure one 

 gallon and weigh ten pounds ; and over an acre its weight would be 100 

 tons, and over a square mile 60,000 tons ! 



These figures will enable us to form some idea of the quantity ol 

 water which the earth receives from a shower of rain, and to understand 

 better the extent of the refreshment which even a gentle shower brings 

 to the parched ground after a spell of summer heat. 



Note. — The lecture was illustrated by a large number of photographic slides and 

 maps, which are not reproduced. 



0 2 



