Apeil 7, 1911] 



SCIENCE 



517 



modes of manufacture reach a stage which 

 we may call practical perfection, rela- 

 tively soon after the initial discoveries are 

 made which give theln their first impetus. 

 After this point is reached the improve- 

 ments are few or none (and if any occur, 

 they come from an outside source, as the 

 application of power to the loom). Ex- 

 amples are abtindant: the hoe and other 

 simple farming implements; the safety 

 bicycle ; the sewing machine ; the aeroplane. 

 It must, of course, be presupposed that 

 suitable materials for manufacture have 

 been previously discovered and are at 

 hand, or can be quickly adapted. In such 

 cases as these the opportunities of later 

 generations to develop and improve are 

 meager ; but the limitation is not of the in- 

 ventors, but of the things themselves. 



For many years the great pyramid of 

 Egypt was held up to the youth in all lands 

 as an example of what had been accom- 

 plished by ancient peoples and which could 

 not be duplicated to-day. It was held in 

 fact that the ancient Egyptians were pos- 

 sessed of mechanical knowledge and ap- 

 pliances unknown to us. We must all 

 concede that the great pyramid is a re- 

 markable, if useless, piece of architecture, 

 laid out with extreme precision and carried 

 to its completion in a masterly way. But 

 it turns out that the Egyptians of the Old 

 Kingdom possessed rather limited knowl- 

 edge of mechanics, not having even de- 

 veloped the movable pulley. The great 

 pyramid was built by man-power multi- 

 plied many thousand times. Finally, can 

 it be considered a greater work than a great 

 railway system or battleship? 



That arts have been temporarily lost at 

 least for practical purposes is true. The 

 history of industry has not yet been 

 written — possibly it is too great a task — 

 and adequate data have not been collected 

 and hence are not available, but it seems 



true from the information available that 

 there has been a remarkable continuity in 

 industrial processes in spite of many ad- 

 verse circumstances. 



"War is probably the greatest cause of 

 breaks in the continuity of manufacturing 

 processes and the arts of peace, and if we 

 are to believe past records, the domination 

 of theological systems or religious dogma- 

 tism has been and is the most effective in- 

 fluence in restraining the development of 

 scientific methods of inquiry and conse- 

 quently progress in the arts. On the other 

 hand, commerce and the migrations of 

 peoples have been effective in spreading 

 industries. War destroys commerce, but 

 often causes migrations, and hence has 

 been an active influence in the spreading of 

 industry as well as in checking it. War 

 has also imposed new civilizations on old, 

 and thus caused an unnatural intercourse 

 between two civilizations, which would 

 naturally result in the extension of knowl- 

 edge of the industries peculiar to each. 



Let us examine for a few moments some 

 of the arts claimed to be now lost. The 

 knowledge of a process for hardening cop- 

 per is commonly ascribed to many ancient 

 and prehistoric peoples and is devoutly 

 believed in by many persons. Now in the 

 first place if this knowledge was formerly 

 possessed we have no direct evidence of it, 

 for the copper implements which have 

 come down to us are no harder than those 

 we might make ourselves to-day. A metal 

 may be hardened in two ways : by physical 

 treatment or by alloying it with other 

 metals or substances. Copper may be 

 hardened to some extent by hammering, in 

 the same way that many other metals may 

 be hardened. The common alloys, bronze 

 and brass, are harder than the pure metal. 

 It is probable that ancient peoples used the 

 process of hammering to harden copper 

 and it is certain that they made use of the 



