During the whole of our drift I paid great attention to this ice, not only with respect to its motion, but to its formation and growth as well. In the Introduction of this book I have pointed out that, even should the ice pass year after year in the cold Polar Sea, it could not by mere freezing attain more than a certain thickness. From measurements that were constantly being made, it appeared that the ice which was formed during the autumn in October or November continued to increase in size during the whole of the winter and out into the spring, but more slowly the thicker it became. On April 10th it was about 2.31 metres; April 21st, 2.41 metres; May 5th, 2.45 metres; May 31st, 2.52 metres; June 9th, 2.58 metres. It was thus continually increasing in bulk, notwithstanding that the snow now melted quickly on the surface, and large pools of fresh water were formed on the floes. On June 20th the thickness was the same, although the melting on the surface had now increased considerably. On July 4th the thickness was 2.57 metres. On July 10th I was amazed to find that the ice had increased to 2.76 metres, notwithstanding that it would now diminish several centimetres daily from surface melting. I bored in many places, but found it everywhere the same--a thin, somewhat loose ice mass lay under the old floe. I first thought it was a thin ice-floe that had got pushed under, but subsequently discovered that it was actually a new formation of fresh-water ice on the lower side of the old ice, due to the layer of fresh water of about 9 feet 9 inches (3 metres) in depth, formed by the melting of the snow on the ice. Owing to its lightness this warm fresh water floated on the salt sea-water, which was at a temperature of about -1.5° C. on its surface. Thus by contact with the colder sea-water the fresh water became cooler, and so a thick crust of ice was formed on the fresh water, where it came in contact with the salt water lying underneath it. It was this ice crust, then, that augmented the thickness of the ice on its under side. Later on in the summer, however, the ice diminished somewhat, owing to melting on the surface. On July 23d the old ice was only 2.33 metres, and with the newly formed layer 2.49 metres. On August 10th the thickness of the old ice had decreased to 1.94 metres, and together the aggregate thickness to 3.17 metres. On August 22d the old ice was 1.86 metres, and the aggregate thickness 3.06 metres. On September 3d the aggregate thickness was 2.02 metres, and on September 30th 1.98 metres. On October 3d it was the same; the thickness of the old ice was then 1.75 metres. On October 12th the aggregate thickness was 2.08 metres, while the old ice was 1.8 metres. On November 10th it was still about the same, with only a slight tendency to increase. Further on, in November and in December, it increased quite slowly. On December 11th the aggregate thickness reached 2.11 metres. On January 3d, 1895, 2.32 metres; January 10th,