96 SALT-MAKINO. ., f T! 



moment dividing the waters of every navigable 

 stream, and the waves in every ocean, in and be- 

 tween all highly-civilized and active countries ; and 

 if, when one is in St. Paul's, " look around" be 

 enough of reminiscence for the genius of Sir Chris- 

 topher Wren, climb the highest mountain, get the 

 most ample range of land and sea ; and, in what part 

 soever of the busy world it may be, " LOOK AROUND" 

 will still be the epitaph of James Watt. 



But what he and his co-operatives have done i 

 but a single series of the applications of that one 

 property of water. Those applications are very 

 many, and our salt-making is one and a highly im- 

 portant one ; and there are places where, if the peo- 

 ple could find materials, they would prize the making 

 of salt more than the making of gold. It is reported 

 that there are some tribes in Africa who give away 

 gold-dust, but reckon value in salt as we do in money. 

 Well, the moment that the water is raised to the 

 boiling point, it will receive no more heat into its 

 substance, or allow any more to pass through with- 

 out exerting the resistance to which allusion has 

 been made ; and if it is not everywhere resisted in 

 return by something stronger than its own resist- 

 ance, a portion of the water goes off, and carries 

 the heat along with it, so that the water where it 

 just begins to mingle with the air is far hotter than 

 it is at the bottom of the vessel. Every one has 

 noticed the force with which the steam of water in 

 a teakettle issues from the spout, and may have seen 

 the force of boiling water drive off the cover of a 

 saucepan ; and it is said, and possibly it is true, that 

 the discovery of the steam-engine was owing to one 

 or other of these ; but when, as in boiling brine for 

 salt, the surface of the water is freely exposed to 

 the air, the heat and water go off together ; and if 

 the boiling were continued long enough, the water 

 would pass entirely into the atmosphere. Salt does 

 not pasg so easily into vapour as water ; and, there- 



