5i8 



NATURE 



[August 29, 19 18 



time, some of which were of a very doubtful character. 

 An interesting occurrence of free petroleum was 

 brought to my notice in 1892. It took the form of a 

 sudden infilux of some hundreds of gallons of light- 

 coloured oil into a well which was the source of the 

 water supply of an isolated dwelling-house standing 

 on high ground near Shepton Mallet. Another caise, 

 which is certainly genuine, is that of the oil find in 

 a test-boring made for coal at Kelham, near Newark. 

 From this bore-hole, which at a depth of between 

 2400 ft. and 2500 ft. had penetrated a bed of porous 

 sandstone, a flow of characteristic crude petroleum 

 amounting to five or six gallons a day took place. 

 The much-advertised discovery at Ramsey, near 

 Huntingdon, cannot be included in the same category,' 

 for the oil had unquestionably leaked from an adjacent 

 store. 



It may confidently be asserted that in certain parts 

 of Great Britain the geological conditions are con- 

 sistent with the existence of valuable stores of 

 petroleum, but doubt has been expressed as to whether 

 the drilling operations which the Government has decided 

 to undertake will be attended with success. It is, 

 however, admitted that the only conclusive test is 

 that of the drilK Some months ago Lord Cowdrav 

 publicly announced his belief that oil may be found 

 in commercial quantities in Great Britain, and stated 

 that his firm was prepared to spend 500,000/. on 

 exploration and development if certain areas were 

 reserved to them. 



Even if we should be unsuccessful in finding free 

 oil, we know that we have abundant stores of 

 bituminous minerals from which oil can be obtained 

 by destructive distillation. 



For centuries petroleum has been raised from hand- 

 dug wells in Burma. Rumania, and Galiria. In the 

 days when King Thebaw reigned in Burma the 

 winning of petroleum bv hand-digging In the 

 Yenangyaung district was an important source of 

 revenue. 



This primitive system of nroductlon has b^en super- 

 seded by the introduction of modern m.ethods of drill- 

 ing, in which steam-driven machinery is employed. 



The drilling of petroleum wells has been brought 

 to such perfection that depths of a mile or more may 

 be reached without serious difficultv in a moderate 

 length of time, but the vield of oil needs to be con. 

 siderable to render drilling to such depths a profitable 

 undertaking. Four vears ago there were In the 

 Boryslaw-Tu^tanowlce oilfield of Galicia sixteen wells 

 of a depth of more than 5000 ft., and one was then 

 \ieldlng oil from strata which had been reached at 

 58-7:^ ft., or nearly a, mile and a furlong. 



It not Infrequentlv happens that oil Is met with 

 on comoletlon of the well under such high pressure, 

 sometimes several hundred pounds on the square inch, 

 that the flow Is uncontrollable. Most of us have seen 

 pictorial renresentatlons of the famous oil-fountains of 

 Baku, but less Is known of similar occurrences else- 

 where, which were of an even more remarkable 

 character. A fountain In the Groznl oil-field In the 

 northern Caucasus, which began to flow In August, 

 i8q5, was • estimated to have thrown uo during the 

 fii-st three days more than 4,500,000 gallons, or about 

 18.500 tons, of oil a day. It flowed continuously, but 

 In graduallv diminishing quantitv, for fifteen months, 

 quicklv destroving the derrick, and afterwards 

 periodically. When I visited the spot In April, iSqy, 

 there was still an occasional outburst of oil and gas. 

 To save the enormous volume of oil ejected an army 

 of w-orkmen was emploved day and night in throwing 

 a dam across the vallev, so as to form a gigantic 

 reservoir. This dam gave way, and a second was 

 constructed below It; a third, still lower down the 



XO. 2548, VOL. lOll 



valley, being afterwards added as a measure of pre- 

 caution. 



Probably the most sudden and violent of the out- 

 bursts of oil which have been experienced is that 

 which occurred in 1908 on the San Diego property of 

 Messrs. S. Pearson and Son (Lord Cowdray's firm) in 

 Mexico. In the early morning of July 5 in that year 

 oil was struck in a well known as No. ;^ at a depth 

 of 1824 ft. The pressure gradually increased, and in 

 fifteen or twenty minutes the ground round the well 

 began to tremble. In various places, some so far 

 distant as 250 ft. from the well, fissures appeared, 

 through which oil and gas were emitted. One of 

 these fissures extended under the boilers, and although 

 the fires had been drawn the gas ignited. The flame 

 was Immediately communicated to the outflowing 

 oil, and the well burned for a period of fifty-eight days 

 with an estimated loss of 3,000,000 barrels of oil. 



The flames reached a height estimated at 1460 ft., 

 with a maximum breadth of about 480 ft. So brilliant 

 was the light emitted that at 9.40 p.m. on July 8 

 persons on board a vessel at anchor in the Tamiahua 

 lagoon, a distance of nearly eleven miles from the 

 well, were able to read a newspaper by it. This is the 

 more remarkable when it Is considered that the ap- 

 proximate limit of distance at which an object iqo ft. 

 high is visible to a spectator at sea-level Is a little 

 more than twelve miles, so that unless the light from 

 the burning well had been reflected from smoke or 

 cloud, only the upper part of the column of flame could 

 have had Illuminating effect at the distance recorded. 

 Besides ejecting the large quantity of oil mentioned, 

 the well yielded a considerable volume of water, esti- 

 mated to reach at times nearly 1,500,000 barrels daily. 

 This great flow of liquid carried away from the sides 

 of the well solid matter estimated approximately at 

 2,000,000 tons. On August 31 the flow of oil tem- 

 porarily subsided, and it became possible to extin- 

 guish the fire by means of sand pumped into the crater 

 with centrifugal pumps. On 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 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 fifty 

 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, and has evidently been forced up from 

 underlying beds by lateral pressure through fis- 

 sures resulting from the local yielding 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 dis- 

 tortion or collapse of the timbering of the galleries. 

 As an Illustration of this It Is recorded that in one 

 mine the perforation 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. 



Crude petroleum varies greatly in character, some 

 descriptions being of pale colour and highly mobile, 

 whilst others are almost black and viscid. The 

 specific gravltv appears to range from 0-771 to t-o6. 



As regards its chemical composition, petroleum con- 

 sists essentially of carbon and hvdrogen, together with 

 oxvgen, and varving amounts of nitrogen and sulphur. 



