344 Sir Boverton Redwood [June 7, 



temporarily subsided, and it became possible to extinguish the fire 

 by means of sand pumped into the crater with centrifugal pumps. 

 Oil September 26 the area of the crater was about 15,000 square 

 metres, and on January 28 of the following year, about 117,600 

 square metres. The two following photographs show Mexican 

 soldiers walking through the fissures caused by the eruption, and the 

 crater as it appeared when the fire was extinguished. 



The deposit of ozokerite in Boryslaw, Galicia, is unique, although 

 the mineral occurs in other localities in that country, as well as in 

 Russia and in Utah. The Boryslaw^ deposit underlies a pear-shaped 

 area, the central and richest part of which is about 50 acres in 

 extent, but this is surrounded by an outer zone of less productive 

 territory, which increases the area of the workable field to about 150 

 acres. The ozokerite occurs in veins varying from extreme tenuity to 

 many feet in thickness. It is usually plastic, as shown by the speci- 

 men on the table, and has evidently been forced up from underlying 

 beds by lateral pressure, through fissures resulting from the local yield- 

 ing of the marl to the compressive strain. The pressure which still 

 exists is attested by the viscous flow of the ozokerite in the mines, and 

 by the frequent distortion or collapse of the timbering of the galleries. 

 As an illustration of this it is recorded that in one mine the perfora- 

 tion by a miner's pick of a thin impervious stratum of rock forming 

 the floor of a gallery resulted in the gradual appearance of a vertical 

 stalk of ozokerite, which for a long time was replaced when it was 

 removed. This curious appearance of growth gave the name of 

 Asparagus Mine to the working. The mining of ozokerite was 

 formerly carried out in the primitive fashion shown in this locally- 

 constructed model by a large number of proprietors, each of w^hoQi 

 had acquired mining rights over a small area which frequently 

 included the dwelling-house. The industry was essentially a 

 domestic one, for it was carried out by the whole family, the sons 

 doing the underground work, w^hilst the wife and daughters assisted 

 by working the windlass and blowing machine, and the father sat at 

 a table and kept the accounts. It w^as the practice to sink a shaft to 

 the ozokerite veins, and to drive from the bottom a gallery into the 

 deposit, which was then mined by the pick. The great pressure 

 exerted by the semi-fluid ozokerite necessitated very heavy timbering, 

 and when I visited tlie locality in 1891 I saw timbers nearly a 

 foot square which had been broken into matchwood by the strain to 

 which they had been subjected. Sometimes the ozokerite suddenly 

 burst into the workings and overwhelmed the miners, and it is 

 reported that men have been unexpectedly raised from the bottom of 

 the shaft to the surface of the ground by such an influx. The 

 horizontal galleries could not be driven further than a few yards on 

 account of the risk, and because of the proximity of the properties. 

 Over the mouth of the well was fixed a windlass carrying a wire 

 rope, to each end of which was attached a bucket used in drawing 



