Vegetable Stanch, 5 3 



Experiment XIX. 



In order to find out the quantity of c Dew 

 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 3 they in- 

 creafed in weight by the night's dew 180 

 grams, anddecreafed in weight by the evapo- 

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



N. B. I fct 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 on 

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

 tity of Dew falls on a furface of water, than 

 there does on an equal furface of modft earth, 

 The evaporation of a furface of water in 9 

 hours winter's dry day is 2 \ of an inch. 

 The evaporation of a furface of Ice, fet in 

 the fhade during nine hours day, was 3 *\. 



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 



