CHAP. XVIII MINING PROPHECIES 375 



of Leadville. I was using a geological map, on the com- 

 paratively large scale of four miles to the inch, which had 

 been prepared by the United States Geological Survey.^ It 

 had only been issued in 1878, nevertheless Leadville was not 

 marked in it. It was not till I recognised that a group of 

 ruined shanties at the entrance to California Gulch marked the 

 site of Oro City, that I could determine the position of the 

 wealthiest town in the Rocky Mountains. The country had 

 been surveyed by the official geologists of the United States, 

 and a number of practical miners had lived for years in the 

 distribt, without discovering that beneath the very slope on 

 which their camp was pitched, lay what is now the most 

 productive silver mine in the world. 



The history of the Comstock Lode ^ is even more 

 instructive. Some alluvial gold was found beside it in 1850 ; 

 in 185 I colonies of miners settled in the district and worked 

 there; but it was not till 1858 that it was accidentally dis- 

 covered that they were living beside a silver lode, which 

 subsequently proved to be the richest metalliferous deposit 

 known in mining history. 



It would therefore be absurd at the present time to express 

 any opinion on the mineral resources of British East Africa. 

 As gold is one of the most universally distributed of metals, it 

 will no doubt be found. Many of the quartz reefs look promis- 

 ing, but most of the rocks which have been described as such 

 are really quartz pegmatite veins. Silver is more likely to occur 

 in the volcanic region, for in the United States it is generally 

 associated with the " propylites," which are very extensively 

 developed in East Africa. Silver and lead exist in the hills 

 near Mombasa, where some trial borings and shafts have been 

 made, and I found some thin seams in the Sabaki valley. 

 Graphite is widely distributed, and near Tzavo it is common ; in 

 one place I found a few crystals of cassiterite or tinstone, but 

 it is not probable that either mineral is sufficiently abundant 

 to pay for working. Iron ores occur in considerable quantity 

 all over the country, but there is no proper fuel with which to 



1 " Geol. and Geog. Surv. of Territories," Geol. and Geog. Atlas of Colorado, United 

 States. 



^ A good summary of the history of this lode is given in the fourth chapter of Ed. 

 Suess's Die Ziikunft des Silbers, VV^ien, 1892, pp. 67-82. The standard authority is 

 Lord's Comstock Miners and Mining. 



