of painstaking execution, but neither he nor anyone else could tell what it was. Union-jacks, twelve-ton guns, and highly mythical polar bears, were of course common. These decorations were most useful in identifying the various men—no easy matter when all were dressed alike, and every face was swollen and blistered with sun and frost, and blackened with stearine smoke. On 7th April, some difference of temperature in the still air treated us to a display of mirage. Almost all day long, as we marched forwards, the conical mountains of Cape Joseph Henry raised themselves up in pale shadow against the sky, and spread out into great flat table-lands, spanning the valleys with bridges, and constantly flickering into new shapes. [Illustration: PLATE XIII.—ON THE NORTHERN MARCH, APRIL 8, 1876.—p. 60. On the sixth day’s march of the united northern and western parties from the ship, this sketch was outlined in pencil while the sledges passed across a floe, little if at all under one hundred and fifty feet in thickness. Like most heavy floes, its edges were piled with rubble ice, cemented and smoothed off with snow-drift, showing a perpendicular wall outside, but sloping inside to the general undulating surface. The easiest road lay right across it, and with the aid of picks a natural gap in its walls was soon converted into a practicable path. The united crews of the “Bulldog” and “Marco Polo” are hauling the latter sledge down through the gap, while the “Challenger’s” and “Poppie’s” have just reached the spot with the first of their sledges.] On the seventh day’s march we crossed a floe so much raised above its fellows that it got the name of “The Castle.” Its surface was about an acre in extent, and, judging from its height over the water, it could not be less than one hundred feet—perhaps one hundred and fifty—in thickness. It was walled in all round by lines of _débris_, piled upon its edges and cemented together with snow, perpendicular outside, but sloping inwards, so that the inside looked like a vast saucer. The easiest road for the sledges lay right across it. Several breaches occurred in its walls, and with the aid of picks they were soon made practicable. A sketch made as the boats passed across represents a scene familiar to many of our sledge parties, for “Castle Floe” was subsequently crossed on no less than thirteen separate occasions (Plate No. 13). [Illustration: CREVASSE NEAR CAPE JOSEPH HENRY.]