Reference to the Supply of Large Towns. 307 



solidified, they would form in one year a square column 9 

 feet in diameter and 140 feet high." If we apply this cal- 

 culation to all mineral springs, as well as rivers loaded 

 with their small but constant amounts throughout their 

 immense volume, we should find, that the process which is 

 carrying mineral matters out of the soil and into the sea 

 is not by any means one producing small effects. 



I am not permitted by my time and the amount of space 

 which can be given to this part of the matter, to investi- 

 gate the fact that besides carrying out the soluble matters, 

 water assists in the chemical decomposition of interior 

 rocks thus bringing them into solution also. I have said 

 that this process of filling up the bed of the ocean is still 

 going on. Besides mineral springs every gallon of river 

 of spring water that has its five or fifty grains of solids 

 carries them from the mountains and plains to be de- 

 posited finally in the bed of the ocean. Each season with 

 frost disintegrates new material and fits it for the next 

 year's floods to remove. In our inland oceans the process 

 goes on at a measurable rate. In the great Salt lake 

 where like the ocean, inlets are pouring their streams and 

 no outlet save evaporation removes them and that only 

 lifts the pure water, we find the lakes year by year be- 

 coming a stronger brine ; in some of them the point of 

 saturation has been reached, and alkaline salts are actually 

 crystallizing on their , bottom and along the shore. Still 

 further, in the same locality we find beds of salt filling up 

 the basins of ancient seas ; here the work is done ; the sun 

 has evaporated pure water from the lake and left its 

 dissolved matter to fall to the bottom, until the evaporation 

 exceeded the supply by rain. This process is going on in 

 the larger inland oceans of the Eastern Continent. 



" The sea of Aral is diminishing rapidly. The Cas- 

 pian sea though it receives through seventy mouths the 

 majestic volume of the Volga the largest river in Europe 



