NATURAL RAIN-MAKERS. 



6 43 



sonry, and they course across the sky at higher speed than man 

 can travel. A locomotive can travel a mile in thirty-seven sec- 

 onds, a fast yacht in about twice that time, and a swift torpedo 

 boat in one hundred and ten seconds. The upper clouds move with 

 an average velocity of a mile in thirty-six seconds, and have been 

 observed moving as rapidly as a mile in eighteen seconds. Equally 

 remarkable are the plastic walls of these aerial reservoirs. No 

 courses of heavy stone and mortar are to be found ; but in their 

 stead drops of water so minute that a thousand of them side by 

 side would not extend farther than one inch. If the temperature 



Alto-cumulus. 



was low during the building of the cloud, the water drops are 

 changed into ice spicules and snowflakes. 



From such reservoirs the rain falls as a rule harmlessly. A col- 

 lapse, which rarely occurs, is known as a cloud-burst. Then, the 

 deluge destroys life and property, sweeping all before it. 



If we were able to control the valves and vents of this tre- 

 mendous pump-reservoir, we could cause rain at will and shut off 

 the downpour at pleasure. But hardly yet may we hope to mas- 

 ter the rain. Rain- makers of our time bang and thrash the air, 

 hoping to cause rain by concussion. They may well be com- 

 pared to impatient children hammering on reservoir walls in a 

 vain endeavor to make the water flow. Rain-control is a scien- 

 tific possibility. Successful rain engineers will come in time, we 



