TRANSACTIONS OF SECTION G. 673 
probability of the acquisition of territorial and mineral rights or possessions 
bringing material gain to the undertakers. The rights of such enterprises are well 
known, and capital can be obtained with or without national support, as the case 
may be. On the other hand, the explorer into the depths of the earth has no 
rights or monopolies beyond the mineral rights of the land he has purchased over 
his boring ; further, it is improbable that he can obtain any patent of substantial 
value for his methods of boring to great depths. To succeed in the undertaking a 
great expenditure of money must be incurred, an expenditure far greater than that 
of an exploring expedition, and analogous to that of a military expedition or a 
small invading army, and to raise this sum the pioneers have practically no 
security to offer. For if they succeed in finding rich deposits of precious minerals 
in greater abundance, or succeed in making some geological discovery associated 
with deep borings, they gain no exclusive title to these under existing laws. Any 
other person or syndicate acting upon the experience gained could sink other shafts 
in other places or countries, and, benefiting by the experience gained by the 
pioneers, could probably carry out the work more advantageously, and thus 
depreciate the first undertaking or render it valueless, as has often occurred before, 
Let us consider more closely some of the essential features of sinking a shaft 
to a great depth, for I think it will be seen that it presents no unsurmountable 
difficulties beyond those incidental to an enterprise of considerable magnitude 
involving the ordinary methods of procedure and the ordinary methods adopted 
by mining engineers. That there would be some departures from ordinary 
practice on account of the great depth itis true, but these are more of the character 
of detail. On the design of this boring I have consulted Mr. John Bell Simpson, 
the eminent authority on mining in the North of England. The shaft would be 
sunk in a locality to avoid as far as possible water-bearing strata and the necessity 
of pumping. It would be of a size usual in ordinary mines or coal-pits. The 
exact position of such shaft would require some consideration as to whether it 
should commence in the primary or secondary strata. It would be sunk in stages, 
each of about half a mile in depth, and at each stage there would be placed the 
hauling and other machinery, to be worked electrically, for dealing with each stage. 
The depth of each stage would be restricted to half a mile in order to avoid 
a disproportionate cost in the hauling machinery and the weight of rope, as well 
as increased cost in the cooling arrangements arising from excessive hydraulic 
pressures. At each second or third mile in depth there would be air-locks to 
prevent the air-pressure from becoming excessive owing to the weight of the 
superincumbent air, which at from two to three miles would reach about double 
the atmospheric pressure at the surface. A greater rise of pressure than this 
would be objectionable for two reasons—firstly, from the inconvenience to the 
workmen ; secondly, from the rise of temperature due to the adiabatic compression 
of the circulating air for ventilating purposes. The air-pressure immediately 
above each air-lock would thus reach to about two atmospheres, and beneath to 
one atmosphere. In order to carry on the transfer of air through the air-locks 
for ventilating purposes pumps coupled to air-engines would be provided, the 
energy to work the pumps being obtained from electro-motors. To maintain the 
shaft at a reasonable temperature at the greater depth powerful means of carrying 
the heat to the surface would be provided. 
The most suitable arrangement for cooling would probably consist of large 
steel pipes, an upcast and a downcast pipe, connected at the top and bottom of 
each half-mile section in a closed ring. This ring would be filled with brine, 
which by natural circulation would form a powerful carrier of heat; but the circu- 
lation, assisted by electrically driven centrifugal pumps, would be capable of 
carrying an enormous quantity of heat upwards to the surface. At each half- 
mile stage there would be a transfer of the heat from the ring below to the ring above 
by means of an apparatus similar in construction to a feed-water heater, or to a 
regenerator constructed of small steel tubes, through which the brine in the ring 
above would circulate, and around the outside the brine in the ring below could 
also circulate, the heat being transmitted through the metal of the tubes from 
brine ring to brine ring. 
1904, xx 
