82 NEW HARBOUR ON THE N.E. COAST OF AUSTRALIA. [March 12, 1860. 



of a very low grade indeed ; and that was this — that none of these animals 

 could live at a greater depth than some fifteen fathoms. They never could 

 have formed the huge bulk of matter which entered into some of those very 

 large corals, some of them as big as the platform upon which he was standing, 

 and rising to such a height that several persons could land upon one of them, 

 and walk about without being in sight of those on the other side of the mass. 

 All the animals that made these great reef-forming corals were confined, when 

 alive, to the comparatively slight depth of fifteen fathoms. How came it, 

 then, that these coral reefs could spring from so great a depth as 2000 feet ? 

 Simply in this way ; that when the commencement of the reef took place, the 

 bottom of the sea, which was now 2000 feet under water, was within the 

 depth of fifteen fathoms ; and that since then the land had been slowly sub- 

 siding and settling downwards so gradually that these little animals continued 

 to live and flourish upon the upper and outer margin of the reef, while the 

 waste and deloris derived from them added to the mass ; and thus the upper 

 surface of the reef was kept up in this comparatively shallow stratum of water 

 just below the level of low tide, while the bottom of it was slowly and 

 gradually sinking down. So that the existence of these coral reefs along the 

 north-east coast of Australia, and over a large part of the neighbouring seas, 

 was one of the proofs we had of the depression of a large portion of the country. 

 Australia, large as it is, was formerly, perhaps, even larger, extending at all 

 events so much farther out on the eastern coast as would be represented by a 

 width of from 10 to 90 miles. Just upon the margin of the then sea, these 

 creatures began to settle and to build ; and, since then, as the country sank 

 and the sea came farther and farther in upon the sloping land, the coral reef 

 increased and increased, so as to keep it up to the dead level of low water. 



He need not enter at any greater length into the consideration of this won- 

 derful physical phenomenon ; but if they would allow him to occupy the 

 attention of the meeting for a few moments longer, he would say a word or 

 two upon the subject of the first Paper, which was so intimately connected 

 with the southern part of Australia. His reason for doing so was this, that a 

 good many years ago he committed himself by printing and publishing a sketch 

 upon the yjhysical structure of Australia. This sketch was founded upon his own 

 observations— upon observations made in H. M. S. Fly during a period of nearly 

 four years that was passed on the coasts — as well as upon the observations that 

 had, previously to 1847, been published on the subject. He had also had the 

 advantage of meeting Captain Sturt upon his return from his great and truly 

 adventurous journey into the interior of the country in the year 1846, and of dis- 

 cussing this point with him. The structure of the country, so far as he knew it, 

 was this : There was a great continuous chain of mountains running along 

 the eastern coast from Bass's Straits to Torres Straits. This eastern coast range 

 was the principal range of the country. It was the one in which there were 

 the highest mountains, namely, the Australian Alps, and it was the one which 

 was the longest range, and which retained a continuous height for the greatest 

 extent. It extended along the whole of the eastern coast, its crests being at a 

 little distance in the interior. In the Melbourne country the ranges of moun- 

 tains, short as they might be, all run north and south ; and that was the case 

 also with the ranges in South Australia, as Colonel Gawler well knew. It 

 was the case certainly with the Darling range in AVestern Australia, where all 

 the hills run north and south. They did not know of any east or west range 

 in Australia, unless it were that high land which Leichhardt reached in the 

 northern part of the country, which seemed to stretch from Cambridge Gulf, 

 and to sink gradually down to the southern part of the Gulf of Carpentaria. 

 That being the disposition of the high lands, let them look for a moment at 

 the direction of the prevailing winds. During the greater part of the year 

 — certainly during all the part that we called summer in England — in the 

 northern part of Australia, lying within the tropics, or north of about 25° s. 



