It remains for me to observe, however, that, whilst these attempts were being made to prosecute inland discovery, Her Majesty’s naval service was actively employed upon the coast.  Captain Wickham, in command of the Beagle, was carrying on a minute survey of the intertropical shores of the continent, which led to the discovery of two considerable rivers, the Victoria and the Albert, the one situated in lat. 14 degrees 26 minutes S. and long. 129 {139 in published text} degrees 22 minutes E., the other in lat. 17 degrees 35 minutes and long. 139 degrees 54 minutes; but in tracing these up to lat. 15 degrees 30 minutes and 17 degrees 58 minutes, and long. 130 degrees 50 minutes and 139 degrees 28 minutes respectively, no elevated mountains were seen, nor was any opening discovered into the interior.  Captain Wickham having retired, the command of the Beagle devolved on Lieut. now Captain Stokes, to whose searching eye the whole of the coast was more or less subjected, and who approached nearer to the centre than any one had ever done before [Note 6. below], but still no light was thrown on that hidden region; and the efforts which had been made both on land and by water, were, strictly speaking, unsuccessful, to push to any conclusive distance from the settled districts on the one hand, or from the coast into the interior on the other.  Reasoning was lost in conjecture, and men, even those most interested in it, ceased to talk on the subject.

[Note 6.  Discoveries in Australia, and Expeditions into the Interior, surveyed during the Voyage of H.M.S.  Beagle, between the years 1837 and 43, by Captain J. Lort Stokes.]

It may not be of any moment to the public to be made acquainted with the cause which led me, after a repose of more than fourteen years, to seek the field of discovery once more.  It will be readily admitted, that from the part, as I have observed in my preface, which I had ever taken in the progress of Geographical Discovery on the Australian continent, I must have been deeply interested in its further developement.

I had adopted an impression, that this immense tract of land had formerly been an archipelago of islands, and that the apparently boundless plains into which I had descended on my former expeditions, were, or rather had been, the sea-beds of the channels, which at that time separated one island from the other; it was impossible, indeed, to traverse them as I had done, and not feel convinced that they had at one period or the other been covered by the waters of the sea.  It naturally struck me, that if I was correct in this conjecture, the difficulty or facility with which the interior might be penetrated, would entirely depend on the breadth and extent of these once submarine plains, which in such case would now separate the available parts of the continent from each another, as when covered with water they formerly separated the islands.  This hypothesis, if I may so call it, was based on observations which, however erroneous they may appear to be, were made with an earnest desire on my part to throw some light on the apparently anomalous structure of the Australian interior.  No one could have watched the changes of the country through which he passed, with more attention than did I—­not only from a natural curiosity, but from an anxious desire to acquit myself to the satisfaction of the Government by which I was employed.