The Earth. 333 



bases, we might measure the whole circumference 

 of the earth. But this would be an enterprise 

 as useless as it is laborious ; for, since we know 

 the relation which any part of a circle bears to 

 the entire circumference, the measure of a few 

 degrees or even of one single degree, will give 

 the measure of the whole. But by applying the 

 telescope to the quadrant, and furnishing it 

 with a micrometer, we are enabled to correct a 

 great many inaccuracies attending this kind of 

 mensuration. The Academy of Sciences at 

 Paris, perceiving from these considerations the 

 necessity of a new measure of the earth, repre- 

 sented the execution of it as a measure of 

 national honour and importance. Monsieur 

 Picard was the person employed to perform this 

 business. He began by measuring the distance 

 between Villejuif and Juvisy ; and this base, 

 which he found to be five thousand six hundred 

 and sixty-three fathoms, was that to which he re- 

 ferred all his calculations. He next placed him- 

 self at Juvisy, and by directing the telescopic 

 sights of his quadrant, the one to the windmill 

 at Villejuif, and the other to the spire of the 

 church at Brie, he measured the angle subtended 

 by these two objects. Leaving his present 

 station, he removed himself to Villejuif, and 

 by measuring the angle between Juvisy and 

 Brie, the distance between Villejuif and Brie 

 was found by calculation to be eleven thousand 

 and twelve fathoms. This distance he made a 

 new base ; and by forming a second triangle be- 



