FIGURE Oa THE EARTH. S2S 



establishing thereby one point extremely interesting in natural 

 philosophy. 



These results, however, did not correspond with sufficient inaccuracy of 

 accuracy for ascertaining with precision the degree of eccen- ^^^ earlier 

 tricity, or even the general dimensions of the earth 5 as might 

 naturally be expected, when we consider the necessary imper- 

 fection of the means then employed in these operations, and 

 the great difficulties that are to be encountered. 



For the purpose of making a nearer approximation to the 

 true dimensions of the earth, and of veritying frmer mea- 

 surements, it is necessary, in some instances, to repeat them, 

 and also to make others in different situations, which may be 

 expected to be improved in proportion to the progress that is 

 made in the means of perfecting the several departments of 

 science. 



At the commencement of the French revolution, men of Grand undeT- 

 science took advantage of the general impulse which the hu- ^^^^°S of ad- 

 man mind received in favour of every species of innovation or in France aud 

 change, and they proposed making a new measurement qf an ^P^'^*" 

 arc of the meridian in France, for the purpose of establishing 

 a new system of weights and measures, which should be per- 

 manent, as being founded on the nature of things. 



A commission, composed of some of the most distinguished directed bya 



members of the Academy of Sciences, was charged to form coin^ssion of 



■' ° the academy, 



the plan of these operations, which were to serve as the basis 



of the new system. They invented new instruments, new 



methods, nt w formulae ; and in short almost the whole of this 



important undertaking consisted of something new in science. 



Two celebrated astronomers, Delambre and Mechain, were ^j^j g^fg^j^^g^ 

 engaged to perform the astronomical and geodetical observa- by Delambre 

 tions, and these they continued as far as Barcelona in Spain. i-eciam. 



The details of their operations, observations, and calculations, 

 were subsequently examined by a committee of men of science, 

 many of whom were foreigners collected at Paris, who con- 

 firmed their results, and by the sanction of such an union of 

 talents, gave such a degree of credit and authenticity to their 

 conclusions, as could scarcely be acquired by other means. 



Since that time, in the year I8O6, Messrs. Biot and Arago, Contmuatioa 



members of the National Institute, were sent into Spain for °'. *^^ ''"^ ^^ 



^ Biot and Ara^ 



the express purpose of carrying on the same course of opera- go to Formea- 

 Y 2 tions *«f»- 



