This letter was the last but two he ever addressed to his mother, and I have not transcribed the whole.  It is long and discursive, considering how much he had on his hands at that time, and how completely he was occupied with the pending expedition.  In his next he refers to some apprehensions expressed by maternal solicitude that his religious convictions might be altered by a friend who entertained extremely different views.  “I intended, my dear mother,” he says, “to have replied at length to one of the remarks in your last, but I fear I must be very brief.  Your idea that I am influenced by—­’s notions of religion is amusingly erroneous.  I never imagined that I could have written anything to warrant such an impression; but it shows how careful we should be to make clear statements so as to avoid being misunderstood.  Mr.—­’s religion is to my mind supremely ridiculous; I can only find two points in its favour, namely, its charity and moral principles.  But these, although admirable in themselves, do not go far towards proving the truth of the theological notions entertained by its adherents.  I can assure you that such ideas of religion are quite as far removed from mine as yours can be.”  His final letter announces the certainty of his being about to start on the enterprise so long projected.  He had hitherto withheld the fact, from a wish not to distress his mother unnecessarily while there was a chance that any unforeseen obstacle might create further delay.

Flagstaff Observatory, Melbourne, July 25th, 1860.

My dear mother,

I am glad to be able to inform you of a matter that you perhaps will not much like, although I do not know why you should object to it.  It is that we expect to start on this exploration trip in a few weeks.  You will find some particulars on the subject in the Argus that I have sent to Charles.  I fancy we shall not be away so long as was at first intended; probably not more than twelve or eighteen months.  I anticipate being able to send you a letter sometimes, as well as to receive yours to me, as they propose keeping up a communication with Cooper’s Creek.  Professor Neumayer will probably accompany us as far as the Darling River, taking an opportunity, at the same time, to prosecute the magnetic survey.  This will make matters very pleasant, as well as being of great advantage to me in many respects.  We shall be travelling through the country in the most favourable and pleasant season, when there is plenty of water, and everything fresh and green.  It will take us about two months to get to Cooper’s Creek.  I do not give up my position in the Observatory, having obtained leave of absence for the time during which we may be engaged in the exploration.  I am sorry I cannot give you more particulars respecting our projected tour, but you will hear enough about it by-and-by.  I received a letter from my father a day or two since, in which he speaks of coming down