Leningrad . : USSR Academy of Sciences Publishing House, 1931. - 154 s. Indispensable Secretary Academician V. Volgin. Preface to the 2nd edition . The first edition of this book quickly diverged, in view of which the Editorial and Publishing Council of the Academy of Sciences decided to issue a second edition, adding it with tables attached to Hayashi's book, to which the State Technical Publishing House kindly expressed its consent. The original text was left unchanged, only in the appendix when calculating the set of the ship's bottom is applied to the compilation of the characteristic equation of the method set forth in my article : "On the numerical solution of the equation by which the frequencies of small oscillations of material systems are determined," for this method most easily and quickly leads to the goal. A. Krylov .