t 



Vegetable Stanch 



53 



Experiment XIX. 





In order to find out the quantity of 7)ew 

 that fell in the night, Aug. 15- at 7. p. m. I 

 chofe two glazed earthen Pans, which were 

 three inches deep, and 12 inches diameter in 

 furface; I filled them with pretty moift earth 

 taken off the furface of the earth j they in- 

 creafed in weight by the night's dew 180 

 grains, anddecreafed in weight by the evapo- 

 ration of the day 1 ounce -j- 282 grains. 



N. B. I fet thefe Pans in other broader 

 Pans, to prevent any moifture from the earth 

 flicking to the bottoms of them. The moi- 

 fter the earth, the more Dew there falls oil 

 it in a night, and more than a double quan- 

 tity of Dew falls on a furface of water, than 

 there docs on an equal furface of moift earth. 

 The evaporation of a furface of water in 9 

 hours winter's dry day is ix of an inch. 

 The evaporation of a furface of Ice, fet in 

 the (hade during nine hours day, was 3 V 



So here are 540 grains more evaporated 

 from the earth every 24 hours in fummer, 

 than falls in Dew in the night 5 that is, in 2 1 

 days near 26 ounces, from a circular area 



E 3 of 







