In the following summer (1845) we again find him on the banks of the Irtysch and the Obi, plunged in Ostiak studies with renewed energy and enthusiasm. After having sojourned for several weeks at Toropkowa, a small island at the confluence of these two mighty streams, he ascended the Obi in July as far as Surgut, where he arrived in the beginning of August. In consequence of the overflowing of its waters, the river had spread into a boundless lake, whose monotony was only relieved, from time to time, by some small wooded island or some inundated village. The rising of the stream had spread misery far and wide, for many Ostiak families had been obliged to abandon their huts, and to seek a refuge in the forests. Those who had horses and cows had the greatest difficulty to keep them alive; and as all the meadows were under water, and the autumn, with its night-frosts, was already approaching, there was scarcely any hope of making hay for the winter. As Castrén proceeded on his journey, the low banks of the river rose above the waters, and appeared in all their wild and gloomy desolation. The number of inhabitants along the Obi is utterly insignificant when compared with the wide extent of the country; and as hunting and fishing are their chief occupations, nothing is done to subdue the wilderness. The weary eye sees but a dull succession of moors, willow bushes, dry heaths, and firs on the higher grounds. Near every flourishing tree stands another bearing the marks of decay. The young grass is hemmed in its growth by that of the previous year, which even in July gives the meadow a dull ash-gray color. Cranes, wild ducks, and geese are almost the only living creatures to be seen. From Siljarski to Surgut, a distance of 200 versts, there are but three Russian villages; and the Ostiaks, who form the main part of the population, generally live along the tributary rivers, or erect their summer huts on the smaller arms of the Obi, where they can make a better use of their very imperfect fishing implements than on the principal stream. Surgut, once a fortress, and the chief town of the Cossack conquerors of Siberia, is now reduced to a few miserable huts, scattered among the ruins of repeated conflagrations. Here Castrén remained till September 24, occupied with the study of the various dialects of the neighboring Ostiak tribes, and then ascended the Obi as far as Narym, a distance of 800 versts. Most of the fishermen had already retired from the banks of the river, and a death-like stillness, rarely interrupted by an Ostiak boat rapidly shooting through the stream, reigned over its waters. Fortunately the weather was fine, at least during the first days of the journey; and the green river-banks, the birds singing in the trees, and the sunbeams glancing over the wide mirror of the Obi, somewhat enlivened the monotony of the scene.