DROUGHT. 189 



croaking give false promises of change. The western 

 clouds diminish as they rise ; for the fountains of heaven 

 are dried up, and cannot supply them with moisture. The 

 black and threatening clouds that before sunset darken 

 the horizon with the signs of approaching rain are deceit- 

 ful, and false is every beautiful signal which is hung out 

 amid the splendors of declining day. There is no truth 

 in any sign that appears in the heavens or on the earth. 



The arrangements of the clouds do not differ essentially 

 from such as appear in ordinary seasons ; but the hue of 

 the heavens is less brilliant, and the tints of yellow and 

 bronze predominate over those of crimson and vermilion. 

 The clouds invariably dissolve soon after sunset, like the 

 steam from boiling water in a clear atmosphere. This 

 dissolution is one of the unfailing accompaniments of 

 drought in all seasons. While the sun is up, there is 

 sufficient evaporation to produce clouds, which continue 

 to increase as long as this moisture is raised by the 

 sun's heat, because the dry region of air above does not 

 absorb them so rapidly as they are produced from below. 

 At the sun's decline all evaporation from the earth and 

 the water ceases. The superfluous moisture of the lower 

 strata of the atmosphere is then precipitated to the earth 

 in the form of dew, and the clouds, which were formed in 

 the daytime, are rapidly absorbed into the dry atmospheric 

 region above them. This process is carried on, day after 

 day, until the whole atmosphere has become saturated, 

 after which rain must soon follow. The first symptoms 

 of this saturation are the continuance of the clouds with- 

 out any diminution of their bulk after sunset. 



The majority of observers have probably witnessed this 

 process of evaporation of the clouds during a dry spell, in 

 the afternoon, a phenomenon which undoubtedly con- 

 tributed to give rise to the old saying that " all signs fail 

 in a dry time." The clouds darken and gather together 



