(FROM A SKETCH BY DR. HAYES.)] [Sidenote: SNOW BLINDNESS.] This mile and a half has, by the tortuous route pursued, been prolonged into near four,--making, with the three times going over it, about twelve. I have not before had so bad a day; and yet the men could not possibly have brought their sledge through at all. The dogs climb the hummocks with the facility of the chamois mounting the Alpine crags. One advantage they possess is, that they are not so heavy as the men and do not so readily break through the crusted snow; and then, the sledges being smaller, are more easily managed. We have reached a most formidable ridge of hummocks which we were too much exhausted to scale; and have camped in a sort of cave made by the crowding over of some ice-tables, thus saving the labor of making a burrow; and it came most opportunely; for Jensen, owing to the uncertain footing, discarded his glasses, and is in consequence suffering from incipient snow-blindness, and would have been unable to assist in digging our usual nightly pit into a snow-drift. Our quarters are very tight and more than usually comfortable,--the temperature being up to within 10° of the freezing point, while, outside, it is 12° below zero. We set out in the morning with much spirit, but are gloomy enough to-night. Such slow progress, with so much labor, is not inspiring. Sleep is our only consolation, and I am glad the temperature is sufficiently high to enable us to repose without freezing. Sleep, that has before drowned many a sorrow for many a weary and care-worn man, has drowned many a one of mine during these past twenty-five days. It is "Tired Nature's sweet restorer," among these ice-deserts, even more than elsewhere; and our sleep is truly the "sleep of the laboring man." Foolish Sancho Panza! yet wise in thy folly! Mankind will long remember thee for thy sage reflection,--"Now blessings light on him that first invented sleep." I will cover myself all over with it, as thou didst; and, if I cannot find in it "heat for the cold," I will cloak with it for a few brief hours the recollection of my disappointed hopes. April 29th. Back again under our last night's shelter. The hummocks were much the same to-day as yesterday, and we made about the same progress--with, however, only half our stores. The load was left buried in the snow, and we returned for the balance; but, upon arriving here, the dogs were not able for the second trip. So here we are under our buffaloes once more in the ice-cave, seeking sleep. It is the best hut that I have ever had. The temperature of the air came up at noon to 4° above zero, and in the sun it was 38°. The thermometer hanging above my head in the cave now shows 31°. April 30th. [Sidenote: CANINE FEROCITY.]