2 76 THE POPULAR SCIENCE MONTHLY 



entirely too small for silver, while many statisticians are using the 

 2,000-lb. ton for both metals. A ton of gold would make a little cube 

 measuring about 14^ inches along its edges, and of silver, one of 17^ 

 inches. Measure these off on your desk ruler and it will become ap- 

 parent into what small packages nature can pack her valuables if she 

 has a mind to, for the golden cube will represent $603,861.22, while 

 that of silver, at the price of 55 cents per ounce, will be worth $16,- 

 041.30. Now, in 1850, just before California and Australia began 

 to produce the former metal in quantity, the world's annual crop of 

 gold was about 60 tons, which could all be stacked away in a small 

 bank vault, having a floor space four feet square and a height of six 

 and one half feet — a mere closet. But in 1906 the crop amounted to 

 675 tons, more than ten times as much, and to accommodate it would 

 require a vault of the same height, but with a floor space of twelve by 

 fifteen feet — quite a good-sized room. As to silver, in the fifty-six 

 years that have elapsed since 1850, the world's annual production has 

 grown from about 975 to 6,360 tons. Carefully piled up in cubes this 

 mass of the white metal would nearly fill up a room 100 feet long, 20 

 feet wide and 10 feet high. 



Iron 



In iron, the metal which is at the basis of the civilization of the 

 day, the record is, if possible, even more remarkable. Reasonably ac- 

 curate statistics of the world's production do not go back of the year 

 1865, when it amounted to 10,009,632 tons. In 1906 the output was 

 64,983,481 tons, showing an increase of nearly 650 per cent, in the 

 forty years. Such figures are not easily grasped by the mind, but let 

 us make the effort. Metallic iron weighs seven and a half times as 

 much as an equal bulk of water. A cubic foot of water will weigh in 

 round figures 62 pounds, and consequently one of iron will tip the 

 beam at 465 pounds. This means that a ton of metal will contain a 

 little more than four and a quarter cubic feet, and that a cube of it 

 measuring about nineteen and a half inches along its edges will weigh 

 a ton. Hence, the output of the year 1906, if put in the form of a 

 solid cube, would contain 279,429,000 cubic feet, and would measure 

 along its edges nearly 650 feet. A city block in New York measures, 

 say, 250 by 500 feet, and its area is about 125,000 square feet, or 

 roughly, three acres. Ten such blocks would be completely covered 

 to the depth of 220 feet by the world's output of iron during the year 

 1906. This would be the equivalent in dimensions of an eighteen 

 sk>ry building, completely covering a thirty-acre tract of land in the 

 metropolis of America. 



But to gain even a more striking impression of what the metal is 

 to modern man, let us figure up the total production of the iron mines 

 of the world during the last eventful forty years. In round numbers. 



