170 PEOFESSOR J. W. JUDD. 



compact, the rock in this part of" the core was soft, and in some places very porous, 

 so that much of it broke up under the boring tools, and, in the 111 feet of boring, 

 only 19 feet 6 inches of solid core was yielded. At the depth of 748 feet another 

 change took place, and the I'ock became very hard and compact in character, l)ut with 

 occasional reversions to the softer type. From this point to the lowest depth reached 

 in the boring, a distance of 366|- feet, the rock was so hard and solid that no less than 

 312 feet of core was brought up, the loss which occmred being evidently largely due 

 to the grinding one on another of the broken fragments of core. Many of the cores 

 from this part of the boring were a foot or more in length ; one (523a), from a 

 depth of a little over 1000 feet, reaching a length of nearly 2|- feet, while a second 

 (678a), from nearly 1100 feet, was over 3 feet in length. 



The disintegrated sandy-looking material, so abundant in the upper portions of the 

 boring, was seen by the aid of the lens to be neither waterworn nor windworn. On 

 the contrary, it was found to be made up of angular fragments consisting of 

 foraminifera and other organisms, whole oi' fragmentary, evidently broken out of a 

 loosely- cemented mass. It became clear upon closer examination that the reef rock 

 in this part had become loose and cavernous througli the removal by solution of the 

 corals and other organisms composed of aragonite, and that the mass, thus weakened 

 and rendered porous, not being able to withstand the action of the boiing tools, had 

 been reduced to a mass of disintegrated j)articles. Tlie few solid fragments brought 

 up consisted almost entirely of more or less perfectly ])reserved calcite organisms. 



In the core-boxes, as sent from Sydney, the disintegrated material washed up from 

 the boring was packed in its proper place between the pieces of core, but as there 

 was some risk of admixture (there being two or three rows of core in each box, only 

 separated by loose laths), we were supplied by Professor David Avith boxes of " sand" 

 carefully collected at every few feet of depth. These "sands" were sifted and had 

 their organisms, wliich were chiefly foraminifera, carefully picked out and studied. 



As it was agreed that the cores obtained from this important })oring should be 

 equally divided between the Sydney Museum and the British Museum, 1 determined 

 to slit each solid core longitudinally, cutting out from tlie centre any slice or slices 

 which might be necessary for microscopical or chemical examination. In the higher 

 portions of the boring, where the proportion of solid core was small, this task was a 

 comparatively easy one ; but when, as was the case in the lowest 400 feet, the core 

 was found to be almost continuous, the labour involved became very great. Attempts 

 were made to get this work done more expeditiously by marble merchants, but the 

 results were not satisfactory and, in the end, it was resolved to avoid all risks by 

 completing the cutting up of the cores in tlie laboratory at South Kensington. This 

 was, however, greatly facilitated l)y using a lapidary's wheel driven by an electro- 

 motor, which was set up at my request by the Board of Education. Some part of 

 the delay in bringing tlie task to an end is, of course, due to the fact that all 

 research work in a college has to be subordinated to the regular teaching. 



