IV 



THE INFLUENCE OF THE DIURNAL ROTATION OF THE 



EARTH ON CONSTRAINED HORIZONTAL MOTIONS, 



EITHER UNIFORM OR VARIABLE 



AN ABSTRACT BY PROFESSOR A. ERMAN OF A MEMOIR BY PROFESSOR 

 N. BRASCHMANN, WITH ERMAN's NOTES THEREON 



[Translated from Archiv fur Wissenschaftliche Kunde von Russland 

 Vol. XXI, 1862, pp. 52-96 and 325-332 1 ] 



The first volume of Braschmann's Theoretical Mechanics, Mos- 

 cow, 1859, combines to such a high degree condensed and precise 

 presentation with abundance and variety of problems that the 

 best interests of the mathematical study of motion demands its 

 broadest possible dissemination 



As an example of the treatment of the problems enumerated 

 above, we choose first the theory of relative motion of a free or 

 restricted mass point and then the application of this theory to 

 the so-called Foucault experiment and to other physical prob- 

 lems arising from the rotation of the earth, which first began to 

 be considered and empirically studied in recent years 



The second practical application that Braschmann makes 2 of 

 his general formula? for relative motion consists (1) in the remark 

 that every mass moving on the earth's surface along a restricted 

 path exerts a horizontal pressure on the boundary of its path 



1 The early publications of William Ferrel relative to the motions of 

 the atmosphere, beginning with 1856, were made accessible by reprints in 

 Professional Papers, Nos. VIII and XII, of the U. S. Signal Service. In 

 these, as in most other memoirs on the subject, the motions of the atmos- 

 phere were assumed to be uniform in velocity, but in 1854-1862 Braschmann 

 and Erman gave a notable enlargement of our ideas. Since that date two 

 elaborate memoirs by Dr. Joseph Finger of Vienna (I, 1877; II, 1880) have 

 given further details of the motions of bodies on a rotating spheroid. 



C. A. 



" See his article in Bull. Imp. Acad. Sci. St. Petersburg, Feb. 3, i860. 



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