126 THE POPULAR SCIENCE MONTHLY 



Of all the extraordinary journeys dreamed by Jules Verne, perhaps 

 that to the center of the earth took us to regions least explored. 



But these deep-lying rocks we can not reach exercise from afar 

 their attraction which operates upon the pendulum and deforms the 

 terrestrial spheroid. Geodesy can therefore weigh them from afar, so 

 to speak, and tell us of their distribution. Thus will it make us really 

 see those mysterious regions which Jules Verne only showed us in imag- 

 ination. 



This is not an empty illusion. M. Faye, comparing all the measure- 

 ments, has reached a result well calculated to surprise us. Under the 

 oceans, in the depths, are rocks of very great density ; under the conti- 

 nents, on the contrary, are empty spaces. 



New observations will modify perhaps the details of these conclu- 

 sions. 



In any case, our venerated dean has shown us where to search and 

 what the geodesist may teach the geologist, desirous of knowing the 

 interior constitution of the earth, and even the thinker wishing to spec- 

 ulate upon the past and the origin of this planet. 



And now, why have I entitled this chapter French Geodesy? It is 

 because, in each country, this science has taken, more than all others 

 perhaps, a national character. It is easy to see why. 



There must be rivalry. The scientific rivalries are always courteous, 

 or at least almost always ; in any case, they are necessary, because they 

 are always fruitful. 



Well, in those enterprises which require such long efforts and so 

 many collaborators the individual is effaced, in spite of himself, of 

 course ; no one has the right to say : this is my work. Therefore it is not 

 between men, but between nations, that rivalries go on. 



So we are led to seek what has been the part of France. Her part 

 I believe we are right to be proud of. 



At the beginning of the eighteenth century long discussions arose 

 between the Newtonians who believed the earth flattened; as the theory 

 of gravitation requires, and Cassini, who, deceived by inexact measure- 

 ments, believed our globe elongated. Only direct observation could 

 settle the question. It was our Academy of Sciences that undertook 

 this task, gigantic for the epoch. 



While Maupertuis and Clairaut measured a degree of meridian under 

 the polar circle, Bouguer and La Condamine went toward the Andes 

 Mountains, in regions then under Spain which to-day are the Eepublic 

 of Ecuador. 



Our envoys were exposed to great hardships. Traveling was not as 

 easy as at present. 



Truly, the country where Maupertuis operated was not a desert, and 

 he even enjoyed, it is said, among the Laplanders those sweet satisfac- 



