70 FIRESIDE SCIENCE. 



account for the almost complete disappearance of 

 these many thousands of tons of bronze ? 



It is generally supposed that the ancients were 

 acquainted with a method of hardening copper, so 

 as to make it subserve the purposes of iron and 

 steel in the working of wood and stone. If this be 

 true, the art is a lost one, as we certainly are igno- 

 rant of any such process. It is, however, hardly 

 probable or possible that this supposition can be 

 strictly true. Modern alloys of copper have been 

 made of great hardness, but nothing that possessed 

 the characteristics of steel. The sword-blades, 

 spear-heads, hatchets, and cutting instruments of 

 the ancients were probably only alloys of copper and 

 tin, which were capable of meeting many wants in 

 the absence of the harder and more refined fer- 

 ruginous metals. It is, indeed, a mystery how they 

 could, with the implements of metal at their com- 

 mand, construct such stupendous works of solid 

 masonry, the remains of which are now seen in all 

 parts of the Old World. They worked in the hard- 

 est stone apparently with as much facility as we do 

 with our steel hammers, drills, and bars. The 

 mystery, however, connected with metallic hand 

 implements is no greater than that regarding the 

 mechanical appliances by which such huge masses 

 of solid rock were detached from the mountain 

 sides, and transported long distances. They had 



