piled for the use of our officials some figures showing the difference between the production of certain metals in the year 1912, the year before the Carranza revolution started, and in the first half of the year 1916. Following is a tabulation of these figures:
| 1912 | FIRST HALF OF 1916 | |||||
| Ore | 5,180,059 | tons | 904,131 | tons | ||
| Gold | 252,843 | ounces | 39,895 | ounces | ||
| Silver | 31,892,735 | ounces | 6,200,339 | ounces | ||
| Copper | 74,984 | tons | 23,156 | tons | ||
| Lead | 70,939 | tons | 2,928 | tons | ||
| Zinc | 46,765 | tons | 11,183 | tons | ||
It will be noted that the foregoing table shows a reduction in the production of two metals of prime necessity in war, copper and lead, of about 38 per cent, in the former and more than 91 per cent, in the lead production. If to the foregoing figures should be added the reduced production of the American mining interests not represented, the loss would, of course, be increased by 50 per cent.
With the present development of the auto-vehicle, rubber is an article of prime necessity, especially in war. The following table prepared by the American companies engaged in producing rubber from the Guayule shrub in Mexico compares the production of the years 1910, which
