214 lEON-OKE RESERVES. 



gradually increase as the lower grade ores and those remote from 

 coal come into use. In the end we shall have to resort to con- 

 centrating processes, by which the iron ore is separated from the 

 rock in which it is disseminated as grains. This upward grade in 

 cost means a downward grade in the utility of the metal in the 

 service of man. Finally, it may be some centuries from now, but 

 surely we shall be forced to an economy in the use of the metal 

 such as was exercised by folk two hundred years ago, wdien, save 

 for what went down at sea, or rusted back to earth, none of it was 

 lost to the arts. In this stage, when it becomes again a precious 

 metal, iron may continue to be the helper of man for an indefinite 

 period, but its power for help will be greatly diminished." 



