NO. u.] MECHANICAL COMPOSITION OF SAMPLES. 29 



brings with it much greater quantities of clay than can be produced by coast- 

 erosion, and in consequence of this clay being present in so comparatively 

 concentrated a degree, a considerably greater percentage of it than would 

 otherwise be the case will sink to the bottom as soon as it comes out into 

 salt water. The result of this is that these samples contain a greater quan- 

 tity of argillaceous matter than any of the others with the exception of No. 

 15, which was taken at a particularly great distance from land. As the process 

 of deposition in these localities must be assumed to be relatively very rapid, 

 the clay has not had time to undergo any appreciable transformation, and has 

 therefore almost all been washed out in a very fine condition. The colour of 

 the clay also leads to the conclusion that the deposition has taken place ra- 

 pidly, all three samples being described as brownish grey, about half-way 

 between grey and brown-grey. 



The curve, however, for all three samples shows a very considerable 

 extension to the right, which must have its own peculiar origin. It cannot 

 be supposed that the rivers themselves have brought these coarser particles 

 with them, for in that case the curves would have had a far more regular 

 appearance, whereas Nos. 2 and 6, at any rate, have a separate maximum 

 at the particles between 005 and 05 mm. The reason of this extension is 

 to be found either in the river-ice or in the particles arising from coast- 

 erosion. The latter seems to be best suited to the form of the curves. 



Nansen (These Reports Vol. Ill, No. 9, p. 294) mentions that the Fram 

 during nearly the whole of her voyage along the coast of Siberia, experienced 

 currents running almost exactly to the SW. in a direction opposite to her 

 course. These currents were related to the winds prevailing at that time, 

 which were likewise contrary. If such a current is at all usual in this 

 region the differences in these three samples just mentioned, can of course 

 be very easily and naturally explained. Material torn loose on the coasts 

 will be carried down by this stream towards the mouths of the Obi and 

 Jenisei and the two localities represented by samples 2 and 6 would in that 

 case be more exposed to the effects of the current than would No. 5, and 

 would in consequence contain much more sandy material. As No. 6 came 

 from a good deal nearer to the Siberian coast, it is naturally somewhat 

 coarser with quite a considerable quantity of particles over 05 mm., than 



