NORTH-WEST PASSAGE.—Letters from Captain Back were received yesterday morning at the office of the Royal Geographical Society, the latest date being the 29th of April last, when the intelligence had just reached him of Captain Ross’s return.

Their contents are of a mixed character. He and his party were all well, with the exception of Augustus, the Esquimaux interpreter, who had accompanied Sir John Franklin in both his journeys, and was now despatched by the Hudson’s Bay Company to join this third enterprize, but perished by the way. The winter had indeed been extraordinarily severe. “We have had,” says Captain Back, “a most distressing winter in this more than Siberian solitude, where desolation reigns in unbroken repose. Even the animals have fled from us, as it were by instinct, and many, very many, of the unhappy natives have fallen victims to famine in situations the most revolting to human nature. The fish also, on which I in some measure relied, left us; in places which we were told never before failed we have not caught a fish; and during the whole season scarcely a living creature has been seen, except on one occasion a raven, which, in wheeling over the house, startled me with his croak, so uniform was the silence around us. I ran out, but when it saw me it screamed, and again made off to the western mountains, in the dark shade of which it was speedily lost. My party has been thus much dispersed in quest of food, and every message has brought me tidings of their encountering severe privations. Mr. M’Leod (an agent of the Hudson’s Bay Company attached to the party) and his young family are at this moment somewhere on the lake, fishing; and you may imagine what it costs me to see them also exposed to the rigours of this severest of all winters, for the mean of three thermometers has been far below the lowest we ever registered in our former expeditions. After this narrative, you may believe that, in spite of all my care and economy, some part of the provisions laid up for our voyage has been necessarily consumed. The most experienced man in the country could not have foreseen this; nor was there any possibility of avoiding it. My anxiety is immeasurable on account of it; but I still hope that the Indians may be enabled to procure us dry food, or in short something that may afford sustenance, so that the fondest wishes of my heart may not be frustrated. Of that, however, in one sense, there is no danger, for come the worst, I can always reduce my men, and go in one boat. Do not, therefore, let this affect you, for I feel confident of overcoming it. Another misfortune is, that pinched as we are for provisions, we must drag our boats and luggage almost 100 miles over rock and ice before we can reach open water. This we have ascertained through the winter; but never mind, this also shall be done, and it will be a new feature in discovery. In our former expeditions we had none of these tremendous obstructions to contend with, though we had to take our bark canoes some distance in sledges. But I have perfect confidence in my men, and they, good fellows, think that I cannot err.

The above was written before the arrival of the express announcing Captain Ross’s return; and, pressed for time, only a few lines are added subsequent to that event. They are, however, so characteristic of the gallant writer, that they ought not to be omitted:—“I have this moment received your despatch, with an account of Ross’s return. I am all gratitude and happiness. My heart is too full to write: but I shall pay attention to all that is recommended to me; of this assure the committee. What a triumph is this return of Ross’s to us all who ‘hoped against hope!’ And what do the croakers say? Will they acknowledge the lesson afforded by it of the power of stubborn perseverance ?” &c. From a private letter which we have seen, it may be interesting to some to add the following scrap:—My day is chiefly spent thus—before breakfast I read a portion of scripture, and afterwards attend to my observations, study, draw, (I have plenty of pencil sketches,) work up my survey, take notes on Aurora, &c. At the same time I have my eye on whatever duty is going on, have an evening school twice a week, and read the service in French and English every Sunday. My guitar is cracked, and jars abominably; but you will not be surprised at this when I add, that I have been obliged to grease my hands daily to prevent their cracking also, for such is the dryness of the atmosphere that nothing can stand it.”

It may also allay the anxiety of friends and relations to add, that Hearne found abundance of game along the banks of the Thlew-ee-cho, so that, as the season advances, Captain Back’s hunters may reasonably be expected to be equally fortunate. His prudence, based on a long experience, may also be relied on, as well as his enterprise. His buoyancy of temper, and the confidence reposed in him by his companions, will support all their spirits. In a word, his task is arduous, more arduous than had been imagined, previous to the receipt of these letters; but it could not be in better hands. And it is very satisfactory to know, from other letters received by the committee of the Hudson’s Bay Company, that ample supplies have been since forwarded to him, which will support him during the ensuing winter. Early next spring he and his whole party will set forward on their return.