OF LA PEROUSE. |2Q, 



Ifle of France, and at the diflance of upwards 

 of a hundred and fifty myriameters to the fouth- 

 ward, had been iz more than that which is ob- 

 ferved on approaching that ifland : this is a very 

 great variation in proportion to the difference of 

 latitude. 



The greateft weflerly variation obferved, was 

 on the 3d of March, 30 30'; our latitude 

 being then 34 30' fouth, and our longitude 

 37 45' eaft: from this point it continued to 

 diminifh, and, in the latitude of 43 fouth, and 

 longitude of 129 eaft, we found no variation; 

 it then became eafterly, and increafed in propor- 

 tion as we advanced to the eafiward. 



The weilcrly variation of the magnetic needle 

 obferved at the point where it was the greater!, 

 had been owing more to the change of longitude 

 than to that of latitude ; while afterwards, till 

 we were under the meridian of the Ifle of France, 

 it feemed to depend much more on the degrees 

 of latitude ; for from the point where it had been 

 the greater!: as far as to the meridian of that ifland, 

 after having made 17 of longitude, and 2, 30' 

 of latitude, the difference of the variation had 

 been only 4 , while in a latitude of 17 more 

 foutherly, the variation had been found u 

 greater than that of the Ifle of France*. 



The phofphorefcence of the fea- water had in 

 this run diminished in proportion to our diftancc 



vol. 1. k froaa 



