The Natural History of Selborne

Lord Howe arrived at Portsmouth with 16 men of war.  He was absent just nine weeks.  If a frost happens, even when the ground is considerably dry, as soon as a thaw takes place, the paths & fields are all in a batter.  Country people say that the frost draws moisture.  But the true philosophy is, that the steam & vaours continually ascending from the earth, are bound-in by the frost, & not suffered to escape, ’till released by the thaw.  No wonder then that the surface is all in a float; since the quntity of moisture by evaporation that arises daily from every acre of ground is astonishing.  Dr Watson, by experiment, found it to be from 1600 to 1900 gallons in 12 hours, according to the degree of heat in the earth, & the quantity of rain new fallen.– See Watson’s Chem. essays: Vol. 3 p. 55. 56