October 23, 1908] 



SCIENCE 



545 



of iron ore it uses. Gold, silver, tin, lead 

 and many other metals, while useful, could 

 be dispensed with, but iron and copper are 

 indispensable at this stage of the world's 

 progTess, and of these two iron is by far the 

 more necessary and the more useful. In 

 1907 fifty-three million tons of iron ore 

 were mined and up to this time seven hun- 

 dred and fifty million tons had been mined 

 in this country. The total amount of iron 

 ore available in the United States is about 

 as follows: In Lake Superior, one billion 

 five hundred million tons; southern dis- 

 trict, two billion five hundred million tons ; 

 other parts of the United States, five bil- 

 lion tons; or a total of about ten billion 

 tons. The highest grade is found in the 

 Lake Superior district and hence this ore 

 is in the greatest demand. In 1907 forty- 

 four million tons were mined in this region, 

 and with the present increase in consump- 

 tion the supply will be completely ex- 

 hausted by 1940 unless new deposits are 

 discovered. Up to the present time one 

 thirteenth of the original supply of iron 

 ore in the United States has been used. 

 At the present rate of exhaustion the total 

 amount in the whole country will be used 

 up before the end of the present century. 

 This includes, however, only that supply 

 which is of a high enough grade to be 

 worked at the present time. After that it 

 will be necessary to use lower grades of 

 ore or we must do what so many European 

 countries do— import from other places. 

 This, of course, would be a great blow to 

 our material prosperity. We have held 

 our position in the industrial markets for 

 iron and steel products on account of the 

 abundance of our iron and coal and the 

 consequent cheap price of both. When it 

 becomes necessary to import either coal or 

 iron, the cost of manufacture will largely 

 increase, and unless conditions are different 

 from those at present, we shall no longer 

 be an exporting nation. It will be neces- 



sary for the engineer to use all of his in- 

 genuity and skill to avert the commercial 

 and industrial disaster which will inevi- 

 tably come when the supply of iron ore is 

 exhausted. This may be done, perhaps, by 

 new methods which will make it possible to 

 use a lower grade of ore and yet obtain the 

 manufactured product at the same price 

 as at present. New alloys of iron will un- 

 doubtedly be discovered by the engineer 

 which will make it possible to obtain the 

 present strength for machines and struc- 

 tures with the use of less material, thus 

 decreasing the amount of ore used. As 

 concrete reinforced by steel takes the place 

 of steel structures, a still greater saving in 

 iron wiU be the result. This is inevitably 

 coming, for the progress in this direction 

 during the past few years has been aston- 

 ishing. The engineer is deeply concerned 

 with methods of transportation and by sub- 

 stituting water transportation for rail 

 transportation the saving in steel is very 

 great, for the same load can be carried by 

 the former with one third the steel in the 

 original plant that is necessary when loads 

 are carried by rail. 



RECLAMATION OF LAND 



The problem of maintaining the fertility 

 of the soil and of enriching the worn-out 

 farming lands of the country is one which 

 belongs to the scientific agriculturist and 

 not to the engineer, but there is one ques- 

 tion connected with the agricultural inter- 

 ests of the country with which the engineer 

 is vitally concerned— that is the reclama- 

 tion of the arid and swampy regions. 

 When the population of a country is sparse 

 people seek the richest farming lands. 

 They use the most exhaustive and least 

 scientific methods of agriculture and the 

 soil is soon depleted, but they are indiffer- 

 ent to this because there are large areas not 

 in use and they can move from the worn- 

 out farm to a new section. But as popula- 



