340 THE POPULAR SCIENCE MONTHLY. 



between the men of science and the men of business, and I am sure 

 that you will pardon me if I draw my illustrations from that subject 

 with which I am most familiar the production of iron. 



In 1856 I had occasion to trace the history of the manufacture 

 of iron, and established what may be termed its law of development, 

 rather rude indeed, but plainly dependent upon the growth of popu- 

 lation and the spread of civilization throughout the world. At that 

 time the annual production of iron had reached about 7,000,000 tons, 

 of which Great Britain produced 3,500,000 tons, and the United 

 States about 1,000,000 tons. The consumption of Great Britain was 

 144 pounds, and of the United States 84 pounds, while the average 

 consumption of the world was only 17 pounds, per head, of population. 

 It was shown that the consumption per head was steadily on the 

 increase, and that consequently the annual production was enlarging 

 so rapidly as to double once in 14 years; and it was predicted, after 

 making due allowances for all the drawbacks, such as the wars which 

 have unhappily taken place in the interval, beyond any possible expecta- 

 tion, that in 1875 the production of iron would surely reach 14,000,000 

 tons. The actual returns show that in 1871 the production amounted 

 to 13,500,000 tuns, and in 1872 the limit 14,000,000 will undoubtedly 

 be passed, so that the estimate made in 1856 is more than realized. 

 Meanwhile the consumption has risen in England to 200 pounds, in 

 the United States to 150 pounds, and in the whole world to 30 pounds, 

 per head. It is not possible to convey a more striking idea of the 

 progress of the world, during the last 17 years, than this statement 

 affords. The consumption of iron measures the progress of c ivilization, 

 and it is impossible not to believe that the whole world will ultimately 

 require as much iron per head as we now use in the United States, when 

 a total annual production of over 70,000,000 tons will be required. But, 

 if these figures seem to be at all wild, no one can for a moment doubt 

 that the next 17 years will double the present annual production of 

 iron, bringing it up to 28,000,000 tons per annum; and I feel quite 

 safe in asserting that the beginning of the twentieth century, which 

 some among you may hope to see, will witness an annual production of 

 over 40,000,000 tons. 



You need not be told that iron is produced at less money-cost in 

 Great Britain than in any other quarter of the globe. This has en- 

 abled her to produce about one-half of the total annual make. Of the 

 7,000,000 tons made in 1855, Great Britain produced 3,585,906 tons, 

 and, of the 13,500,000 tons produced last year, she turned out nearly 

 7,000,000 tons. It it is evident, however, that there are limits in the 

 way of raw material and labor beyond which Great Britain cannot go. 

 While I see no reason to doubt that there will be a steady increase in 

 production, it is evident that she will not be able to supply hereafter, as 

 heretofore, so much as half the annual wants of the world for iron. 

 But, allowing this proportion to Great Britain, there will still remain 



