An Account of the Arcs perpendicular to the Meridian, which 

 are now measurimj on the Continent of Europe. 



It has been known that, for several years past, France, in 

 conjunction with Austria and the governments of Northern 

 Italy, has been engaged in the measurement of two arcs per- 

 pendicular to the meridian, commencing on the shores of the 

 Atlantic. Of these, the southernmost, in the latitude of forty- 

 five degrees, the mean latitude between the equator and the 

 pole, crosses France, Italy, and the Austrian dominions east 

 of the Adriatic, until it impinges on the Turkish frontier ; the 

 other, in the parallel nearly of Paris and Vienna, crosses the 

 territories of France and Austria, until it reaches the Russian 

 frontier. 



The geodesical measurements of these arcs originated in 

 the early part of the present century, and have been since 

 unremittingly prosecuted, excepting during the years 1813 

 and 1814, when the great political events of that period occa- 

 sioned their suspension : on the restoration of tranquillity in 

 Europe they were resumed with increased activity, so as to 

 be now far advanced towards their completion. Since that 

 period also, the necessary operations have been commenced, 

 and carried on in concert by the respective nations, wherever 

 such concert was required, for the determination of the celes- 

 tial amplitudes, corresponding to the portions of the parallels 

 which have been geodesically measured. Within the last few 

 months both series of operations, the astronomical and the 

 geodesical, have been completed on those portions of the arcs 

 which are comprised within the French territory ; and the 

 details, necessarily very voluminous, are in preparation for the 

 press. Meanwhile, public curiosity has been greatly interested 

 to learn the tendency at least of the evidence, which this 

 method of research on the figure of the earth, now for the 

 first time employed, may afford in regard to the amount of 

 the compression ; and in consequence it has been judged 

 proper, by the French authorities, to anticipate the final pub- 

 lication, and to communicate, in the present stage, such par- 

 ticulars concerning the portions completed, on the authority of 



JAN.—MARCH, 1827. N 



