674 REPORT—1904. 
We have now presented to us two alternative arrangements for cooling. One 
arrangement would be to cool the brine to a very low temperature in the top ring at 
the mouth of the shaft by refrigerating machinery, so as to provide a sufficient 
gradation of temperature in the whole brine system, to ensure the necessary flow 
of heat upwards from brine ring to brine ring, and overcome all the resistances of 
heat-transfer, and so maintain the lowest ring at the temperature necessary for 
effectual cooling of the lowest section of the shaft. But a better arrangement 
would be to place powerful refrigerating machinery at certain of the lower stages, 
the function of this machinery being to extract heat from the ring below and 
deliver it to the ring above. This latter method would increase to a very great 
extent the heat-carrying power of the system, which in the first arrangement is 
limited by the freezing temperature of brine in the descending column and the 
highest temperature admissible in the ascending brine column. The amount of 
heat condacted inwards through the rock-wall and requiring to be absorbed and 
transferred to the surface depends on the temperature and conductibility of 
the strata. But there is no doubt that the methods I have indicated would be 
capable of maintaining a moderate temperature in the shaft to depths of twelve 
miles. 
During the process of sinking at the greater depths the shaft bottom would 
require the application of a special cooling process in advance of the sinkers, 
similar to the Belgian freezing system of M. Poesche used for sinking through 
water-bearing strata and quicksands, and now in general use. It consists in 
driving a number of bore-holes in a circle outside the perimeter of the shaft to be 
sunk; through these bore-holes very cold brine is circulated, thus freezing the 
rocks and quicksands and the water therein, and when this process is completed 
the sinking of the shaft is easily accomplished, 
In our case this process would be maintained not only on the shaft bottom, 
but also for some time on the newly-pierced shaft sides, until the surrounding rock 
had been cooled for some distance from the face. 
As to the cost, rate of boring, and normal temperature of the rock, an approxi- 
mate estimate has been made, based on the experience gained on the Rand, but 
including the extra costs for air-locks and cooling :— 
Cost Timein Temperature 
£ Years of Rock 
For 2 miles depth from the surface . 500,000 10 122° F. 
sige CEE 37 ” » 9 ” . 1,100,000 25 152° 
a0 miss x poy cep i . 1,800,000 40 182° 
cometh acy 2 ay let + . 2,700,000 55 212° 
BE ee! shia r Panta) .; . 8,700,000 70 242° 
ee Os; 3 F hal % . 5,000,000 85 272° 
I hope I have succeeded in showing in the short time at our disposal that an 
exploration to great depths is not an impossible undertaking. But my main 
object in discussing the enterprise at some length has been to show that a pioneer 
company would not acquire any subsequent monopoly of similar works under the 
existing patent laws or the laws of any country. 
In the scheme as I have described it, there appears to be nothing that could be 
patented ; but let us suppose that some good patent could have been found that 
was absolutely essential to the success of the undertaking, it would certainly 
have expired before the pioneer company could have reaped any substantial 
return, and probably before the first enterprise had been completed. It follows 
therefore that at the present time there is no adequate protection, or indeed any 
protection at all, for the promoters of many great and important pioneer enter- 
prises, some of which might prove of immense benefit to mankind. 
Let us ask what change in the laws would place great pioneer research works 
on a sound financial basis. A Government grant, except for very special purposes, 
seems to be out of the question, seeing that the benefits to be derived are gene- 
raliy not confined to any one country. An extension of the life of patents, 
which is now from fourteen to sixteen years in different countries, would be 
