industrial progress in the past was dependent largely on the intuition, genius or experience of individuals who, conversant with the problems facing them, devised, sometimes by brilliant master-strokes, sometimes by plodding trial and error, methods to overcome them. In all probability many of the older industries arose almost by accident. Men more observant than their fellows noticed the changes that occurred in nature and set out to produce them deliberately. The fused products sometimes found in the ashes of fires, no doubt led some individual to light fires for the express purpose of producing fused material and so, perhaps, came the smelting industry. Charles Lamb’s Essay on Roast Pig gives a picture of how simple industries may have arisen. It shows also that so long as men confined themselves to observation and imitation and failed to proceed to intelligent deduction and experimentation, the methods by which they were able to attain their ends were likely to be clumsy and costly—so clumsy and so costly that while they could provide something more than had been known before, they could not provide sufficient of the new product to exercise any marked effect except over very long periods. The lessons learned were slow and the production infinitesimal so that we now talk of ages—the Stone Age, the Bronze Age, the Iron Age.