188 nature's jflJMracles, 



sinks to that of boiling water. The amount 

 of energy given up in condensing the nine 

 pounds of vapor into nine pounds of water is 

 equal to 6,720,000 foot-pounds. If this nine 

 pounds of water is now cooled from the boiling 

 point to 32 degrees Fahrenheit we come to the 

 final fall, where the potential energy that is 

 stored in the operation of melting ice is given 

 up suddenly at the moment of freezing, which 

 in nine pounds of water is 993,546 foot pounds. 

 Professor Tyndall, in speaking of the 

 amount of energy that is given up between the 

 points where the constituent gases unite to 

 form nine pounds of water and the point 

 where it congeals as ice, says : " Our nine 

 pounds of water, at its origin and during its 

 progress, falls down three precipices the first 

 fall is equivalent in energy to the descent of a 

 ton weight down a precipice 22,320 feet high 

 over four miles; the second fall is equal to 

 that of a ton down a precipice 2900 feet high, 

 and the third is equal to a fall of a ton down a 

 precipice 433 feet high. I have seen the wild 

 stone avalanches of the Alps, which smoke and 

 thunder down the declivities with a vehemence 

 almost sufficient to stun the observer. I have 

 also seen snowflakes descending so softly as 

 not to hurt the fragile spangles of which they 

 are composed. Yet to produce from aqueous 

 vapor a quantity which a child could carry of 

 that tender material demands an exertion of 



