1818.] of the Profile of Mount Jura. 359 



thus throw light upon and verify each other. This I sometimes 

 did formerly ; but I propose to do it more frequently hereafter, 

 now that I know the advantages of it. I have already given to 

 the public a partial measurement of Mount \ entoux. I mean at 

 present to give the profile of Mount Jura on the line from 

 Geneva to Lons-le-Saunier and the chateau Mirebel. A rapid 

 examination of it which I made in 1813, to ascertain some geode- 

 sical points, furnished me with an opportunity for determining 

 it. I regret that the little time I had at my disposal, and the 

 length of time which an observation of Fortin's barometer 

 requires, did not allow me to make so many as I could have 

 wished. But notwithstanding this great inconvenience, he 

 reader will be astonished at the results which I have obtained 

 from successive observations often made at an interval of several 

 hours, and from other corresponding ones made at Paris, Geneva, 

 and Strasburg. 



The table which I give in the first place exhibits in four 

 columns the principal successive observations, and the corre- 

 sponding ones which I could collect. It will be observed how 

 far my successive heights are from each other.* 



Having interrupted the suite of my observations, I divide 

 them into three series, which I place in the order in which they 

 were made. 



I shall not state here the particular calculations which I have 

 made of all the combinations of the observations in this table. 

 I shall be satisfied with arranging together the results which they 

 have furnished in a single table, the first columns of which give 

 the simple heights of the stations by successive observations. In 

 the four succeeding columns I shall give the absolute heights of 

 these same stations determined from a comparison of the corre- 

 sponding observations made at Geneva, &trasburg, and Paris. 

 The last four columns, in which I shall collect the differences of 

 these results, will show the errors to which we are exposed in 

 unfavourable circumstances, and will enable us to foretell their 

 limits in more advantageous cases ; that is to say, when the 

 corresponding observations are made at places less remote, and 

 when the successive observations are nearer each other in respect 

 to time and horizontal space. 



* We suppress this fable, because its great bulk would render the printing of it 

 rather embarrassing. We shall confine ourselves to the results of the observations. 

 — (Note by the editors of the Bibliotheque Universelle.) 



