THE EARTH. 149 



count for their falling again, is attended with rather more difficulty. 

 We have already observed, that the particles of vapour, disengaged 

 from the surface of the water, will be broken and attenuated in their 

 ascent, by the reflected, and even the direct rays, that happen to 

 strike upon their minute surfaces. They will, therefore, continue to 

 ascend, till they rise above the operation of the reflected rays, whicn 

 reaches but to a certain height above the surface of the earth. Being 

 arrived at this region, which is cold for want of reflected heat, they 

 will be condensed, and suspended in the form of clouds. Some va- 

 ,-ours that ascend to great heights, will be frozen into snow ; others, 

 that are condensed lower down, will put on the appearance of a mist, 

 which we find the clouds to be, when we ascend among them, as they 

 hang along the sides of a mountain. These clouds of snow and rain, 

 being blown about by winds, are either entirely scattered and dispersed 

 above, or they are still more condensed by motion, like a snow-ball, 

 that grows more large and solid as it continues to roll. At last, there- 

 fore, they will become too weighty for the air which first raised them 

 to sustain ; and they will descend with their excess of weight, either 

 in snow or rain. But as they will fall precipitately, when they begin 

 to descend, the air, in some measure, will resist the falling ; for as the 

 descending fluid gathers velocity in its precipitation, the air will in- 

 crease its resistance to it, and the water will, therefore, be thus broken 

 into rain ; as we see, that water which falls from the tops of houses, 

 though it begins in a spout, separates into drops before it has got to 

 the bottom. Were it not for this happy interposition of the air, be- 

 tween us and the water falling from a considerable height above us, a 

 drop of rain might fall with dangerous force, and a hailstone might 

 strike us with fatal rapidity. 



In this manner, evaporation is produced by day ; but when the sun 

 goes down, a part of that vapour which his rays had excited, being no 

 longer broken, and attenuated by the reflecting rays, it will become 

 heavier than the air, even before it has reached the clouds ; and it 

 will, therefore, fall back in dews, which differ only from rain in de- 

 scending before they have had time to condense it into a visible form. 



Hail, the Cartesians say, is a frozen cloud, half melted, and frozen 

 again in its descent. A hoar-frost is but a frozen dew. Lightning 

 we know to be an electrical flash, produced by the opposition of two 

 clouds ; and thunder to be the sound proceeding from the same, con- 

 tinued by an echo reverberated among them. It would be to very 

 little purpose, to attempt explaining exactly how these wonders are 

 effected : we have as yet but little insight into the manner in which 

 these meteors are found to operate upon each other ; and, therefore, 

 we must be contented with a detail rather of their effects than their 

 causes. 



In our own gentle climate, where nature wears the mildest and kindest, 

 aspect, every meteor seems to befriend us. With us, rains fall in re 

 freshing showers, to enliven our fields, and to paint the landscape 

 vith a more vivid beauty. Snows cover the earth, to preserve its 

 tender vegetables from the inclemency of the departing winter. The 

 Jews descend with such an imperceptible fall as no way injures the 

 constitution. Even thunder 'tself is seldom injurious : and .t ; s mteu 



