Table II.

Having at our disposal the solar radiation and the coefficient of transparency of the air from our observations and Smirnov’s observations for different times of the year, and knowing the mean duration of sunshine, one can calculate the sum \(S\) of large calories received from the sun by one square centimeter of a horizontal surface over the course of a month if there were no clouds, and the actual sum \(S'\) of heat, as it is obtained if the actual duration of sunshine is taken into account.

Table III.

Comparing these figures with data for stations of western Europe at the latitude of Tomsk, one can see that in Tomsk the amount of heat falling on a horizontal surface is somewhat (about 8%) greater than in Europe.

Student E. A. Bessonov.

I. Study of the Ice of the Tom River before the 1914 Ice Drift (abstract).

The study was carried out in the same manner as in 1911 and 1912 (B. P. Veinberg, Izv. Tomsk. Tekhn. Inst., 29, 1913, 7+7 pp.) and in 1913 (E. A. Bessonov, Izv. Tomsk. Tekhn. Inst., 35, 1914, 6 pp.). Six blocks of ice were studied; one of them (No. 5) was taken at a place on the Tom River where water from the Ushaika River had free access. The results are expressed in five tables with numerous notes characterizing the individual specimens and the peculiarities of the experiments. The 1st and 2nd tables correspond in content and arrangement to Tables I and II of the articles of 1914; the 3rd gives the results of tests for the fracture of a series of pieces cut in different directions from one and the same horizontal layer; the 4th and 5th give the results of a detailed study of the density and resistance to fracture of a series of cuttings cut from block No. 5. In abridged form these tables give

II. Study of the Ice Drift of the Tom River near Tomsk in the Spring of 1914 (abstract).

“The studies of the ice of the Tom River before the ice drift in the preceding years 1911, 1912, and 1913 were of a purely laboratory character, touching scarcely at all upon the question of studying the general state of the ice drift in connection with the meteorological and geological phenomena accompanying it. Meanwhile, the nearest observations and certain experimental data show that the latter is of primary importance, both from the theoretical and from the practical point of view.”

The present work is an attempt by the author “to trace in this year—alongside laboratory investigations—in greater detail all the phenomena of the ice drift, insofar as this seemed possible,” and contains a detailed description of observations (22,3—16,4) of the phenomena from the beginning of preparation for the ice drift up to the final complete movement of the ice.

III. Results of the Study of the Ice of the Tom River before the Ice Drift of 1915 (abstract).

The studies of this year differed in that, in addition to the fracture of bars perpendicular to the axes of the crystals, i.e. parallel to the surface of the river, bars were taken parallel to the axis of the crystals, and a series of tests was carried out (in the mechanical laboratory of the Institute) on the crushing of cubes of ice. Before the determinations prior to the ice drift, a series of preliminary determinations was made in order to work out the most suitable experimental conditions; at the same time, a considerably greater strength in crushing along the crystallographic axis than in the transverse directions was clearly revealed. The results may be briefly expressed by the following table, in which the figures after the decimal point refer to crushing perpendicular to the axis.

Crushing cubes with different sides did not indicate any dependence of the duration of resistance on size: tests 21.3 gave

Cube side . . . . 3.0  3.5  4.0  4.5  5.0 cm.
Duration of resistance . 67±8 78±2 61±7 78±2 56±3

The results of determinations of resistance to bending are expressed by the following table:

Determinations of density gave the same results as in previous years.

K. B. Veinberg.

Magnetic Declination in Siberia in the XVII and XVIII Centuries (autoreferat)

In addition to the 20 direct observations collected by Hansteen and cited in the summary of B. P. Veinberg (Izv. Instituta issl. Sib., 1, 2, 1920), I used Remezov’s maps, on which the direction of the cardinal points by the magnetic needle is indicated (by comparing the directions of rivers), the map of Petr Godunov, and the orientation of the Alekseevsky Monastery in Tomsk, which was apparently set with its altar to the east along the magnetic meridian. In the table below are given: the number according to the summary, the locality, the values of declination for 1910 and 1829 (from the same summary), and for 1600 (according to Hansteen’s map, in Neumayer’s atlas); the figures in parentheses denote the declination computed from the formula:

\[ \delta=-3^\circ.26+0.03|\varphi-55^\circ|+0.15|\lambda-80^\circ|- \]

\[ -(0.11-2.5\cdot10^{-3}|\lambda-75^\circ|+3.3\cdot10^{-3}|\varphi-55^\circ|)(t-1760)+ \]

\[ +1.5\cdot10^{-4}(t-1760)^2-1.0\sin 0.021(t-1760). \]

This formula expresses the values of declination for 1910 and 1829 with a mean error of ±1°.1, for 1805–1716—±1°.4; 1685–60—±5°.3 and 1600—±1°.3. These errors correspond to deviations from the sche—

¹) Bubbly specimens.