Deep Borinc) in Chalk of Denmark. 173 



Carlsberg Fund iu order that the work might be undertaken. The 

 Frederiksberg District Council promised to pay for the coal used. 

 'The idea was to bore completely through the chalk to the underlying 

 strata, which, it was estimated, would be reached at a depth of 

 1,600 feet. 



The American method of boring was employed. A heavy broad 

 chisel was used, fixed on a heavy iron rod suspended by means of two 

 steel links from a stout manilla rope. Tlie apparatus was worked up 

 and down by machinery iu such a way that the engineer could tell how 

 the chisel worked and could keep it turning round. When enough 

 material had been cut loose it was brought tip by letting down 

 a 'sand pump' or syringe and filling this several times with the 

 chalk suspended in water. Of course, the raateiial became very 

 much pounded up. Large pieces were sometimes obtained either by 

 first boring a small hole and then chipping the chalk into the cavity 

 thus obtained or, when the chisel failed to turn and therefore made 

 a narrow cut, by cutting open with a ring-shaped chisel. 



The boring was 24 inches in diameter for the first 90 feet. It was 

 then reduced to 15 inches. When, in May, 1896, a depth of 1,222 feet 

 was reached, 12 in. tubing of soft steel in 8 ft. lengths was let 

 down nearly the whole deptli (for 1,211 feet), and the boring was 

 continued with a 12 in. chisel. In September, 1901, a depth of 

 1,577 feet was reached. From this point a 9 in. chisel was used. 

 In 1902 the borehole between 1,577 ft. and 1,630 feet was widened 

 to 12 inches, and by this means larger pieces of rock with fairly good 

 fossils were obtained. An attempt to continue the steel tubing 

 downwards was not successful. A depth of 2,742 feet (860*6 metres) 

 was readied in March, 1907. The boring was still in chalk, and 

 beyond this depth the American method of boring was impracticable. 

 The borehole, however, is kept open for a possible later extension 

 by ' diamond boring '. 



The boring took a longer time than had been expected, as either 

 flint or very stiff clayish marl caused great difficulties. Grant after 

 grant was generously voted by the Carlsberg Fund. The State also 

 contributed. The total amount expended was about £8,100. 



It was found that the temperature increased 1° C. for each 

 46-1 metres, and that the increase of temperature was quite uniform. 

 Observations were made for each 50 metres, 



2'he Rocks and Fossils of the Strata through tvhich the Boring passed. 



The value of the evidence as to the thickness of the strata passed 

 through depends largely upon proof that the strata were liorizontal. 

 If the beds were at all steeply inclined entirely fallacious results 

 might, of course, be obtained. We shall see that both tlie lithological 

 and palfeontological evidence offers strong proof that tlie beds were 

 almost, if not quite, liorizontal. It may be mentioned, in passing, 

 that the continuation of the Danian and ' mucronata ' beds across the 

 Sound into Sweden is in itself good prima facie evidence that tliere 

 are no steep folds in the Chalk in this immediate neiglibourliood. 



The rocks show a regular succession in their lithological features. 

 The ' Saltholmskalk ' is met with for 86 feet. Below that 880 feet 



