Convinced of the fruitlessness of all further efforts, Pachtussow bade adieu with a sorrowful heart to the coast, which still stretched out before him in undiscovered mystery, and sailed back again to Archangel on September 20. Soon after his return he fell ill, and four weeks later his mourning friends carried him to his grave. The Arctic Ocean is so capricious that in the following year the walrus-hunter Issakow, of Kem, who had no discoveries in view, was able to round without difficulty the north-eastern extremity of Nova Zembla, but, fearful of encountering the dangers of that dreadful coast, he almost immediately returned. During the two winters he spent in Nova Zembla, the steersman Ziwolka had daily consulted the thermometer, and the result of his observations gave to the western entrance of Mathew’s Straits a mean annual temperature of +17°. Thus Nova Zembla is colder than the west coast of Spitzbergen, which, although still farther to the north, is more favorably situated with regard to the winds and currents, and from five to ten degrees warmer than the high northern parts of Siberia and continental America, which sustain a comparatively numerous population, while Nova Zembla is uninhabited. Hence this want, and the circumstance that the vegetation of these islands scarcely rises a span above the ground, while the forest region still penetrates far within the confines of the colder continental regions above mentioned, are to be ascribed not to the low mean annual temperature of Nova Zembla, but to the unfavorable distribution of warmth over the various seasons of the year. For although high Northern Siberia and America have a _far colder_ winter, they enjoy a _considerably warmer_ summer, and this it is which in the higher latitudes determines the existence or the development of life on the dry land. During the winter the organic world is partly sheltered under the snow, or else it migrates, or it produces within itself sufficient warmth to defy the cold--and thus a few degrees more or less at that time of the year are of no material consequence, while the warmth of summer is absolutely indispensable to awaken life and determine its development.