Vegetable Staticks. 5} 



night -, and more than a double quantity of 

 Dew falls on a furface of water, than there 

 does on an equal furface of moift earth. 

 The evaporation of a furface of water, in 

 9 hours winter's dry day, is T V of an inch- 

 The evaporation of a furface of ice, fet in 

 the fhade during 9 hours day, was - J -p 



Thefe Pans increafed in weight by the 

 night's Dew 180 grains; and decreafed in 

 weight by the evaporation of the day 

 1 ounce, 282 grains. So here are 540 

 grains more evaporated from the earth every 

 l\ hours in fummer, than falls in Dew in 

 the night -, that is, in 21 days near 26 ounces, 

 from a circular area of a foot diameter 5 

 and circles being as the fquares of their ^dia- 

 meters, 10 pounds -j- 2 ounces will in 21 

 days be evaporated from the hemifphere of 

 30 inches diameter, which the Sun-flower's 

 root occupies: Which, with the 26 pounds 

 drawn off by the Plant in the fame time, 

 make 36 pounds, that is, 9 pounds out 

 of every cubick foot of earth, the Plant's 

 roots occupying more than 4 cubick feet ; 

 but this is a much greater degree of drinefs 

 than the furface of the earth ever fuffers for 

 15 inches depth, even in the dried feafons 

 in this country. 



E 7 In 



