784 THE POPULAR SCIENCE MONTHLY, 



average product per man of the furnaces of Great Britain, which for 

 1870 was estimated at 173 tons, is reported to have been 194 tons in 

 1880, and 261 tons in 1884. 



Third. The substitution of steel for iron has resulted in a notable 

 diminution of the consumption of iron for the attainment of a given 

 result, or, in other words, more work is attainable from a less weight 

 of material. Sir Lowthian Bell, in his testimony before the Royal 

 British Commission, stated that a ship of 1,700 tons requires 17 per 

 cent less in weight of pig-iron, in being built of steel rather than of 

 iron, and is capable of doing 7 per cent more work. 



Again, the quantity of pig-iron requisite for keeping a railroad in 

 repair will depend greatly upon the state in which iron enters into 

 construction ; rails of steel, for example, having a far greater dura- 

 bility than rails of iron.* 



A further example of recent economic disturbance consequent upon 

 changes in the manufacture of iron characterized by the Secretary of 

 the British Iron Trade Association, in his report for 1886, as "one of 

 the most remarkable of modern times " is to be found in the rapid 

 disuse of the system invented about one hundred years ago by Henry 

 Cort for converting pig-iron into malleable iron by the so-called process' 

 of " puddling." Twenty years ago the use of this process was almost 

 universal, to-day it is almost a thing that has past ; and the loss of 

 British capital invested in puddling-furnaces which have been aban- 

 doned in the ten years from 1875 to 1885, is estimated to have ap- 

 proximated 4,66*7,000, or $23,333,000, involving in Great Britain 

 alone a displacement, or transfer of workmen to other branches of in- 

 dustry during the same period of about 39,000. 



Copper. This metal touched the lowest price on record in 1886, 

 Lake Superior copper in New York falling from 25 cents per pound 



* Opinions, as yet, vary greatly as to the comparative durability of iron and steel 

 rails. In the testimony given before the British Royal Commission, Mr. I. T. Smith, 

 manager of the Barrow Steel Company, gave it as his opinion that the life of a steel rail 

 is three times that of an iron rail, adding, " My reason for saying so is, that I know that 

 upon the London and Northwestern Railroad, where steel rails have been now in use 

 more than twenty years, they consider it so." 



Sir Lowthian Bell also, in testifying before the commission, on the effect on the iron- 

 trade of Great Britain from the expected longer duration of steel rails, says: "Assuming 

 iron rails to last twelve, and steel rails twenty-four years, instead of the railways now in 

 existence in the United Kingdom requiring 465,648 tons annually for repairs, 232,824 tons 

 will suffice for the purpose. Although this only involves the saving of a comparatively small 

 weight of pig-iron, it means less work for remclting and for our rolling-mills, say to the ex- 

 tent of 4,000 to 5,000 tons per week." The difference in duration of iron and steel rails is 

 not, however, in itself a complete measure of the amount of pig-iron required for renewals. 

 This arises from the fact that an iron rail splits up and becomes useless long before the 

 actual wear, as measured by the diminution of weight, renders it unsafe, which often 

 happens when the loss of weight does not exceed 4 per cent of the original weight. 

 Steel rails, on the other hand, go on losing weight until they arc from 10 to 20 per cent 

 lighter than when they were laid down, before becoming unsafe. 



