j$ VOYAGI IN SEARCH 



trade of Citizen Borda. The facility with which, 

 bv means of crofs observations, is corrected the 

 trror that might proceed from the graduation, 

 gives it a very decided fuperiority over all other*, 

 when it is wifhed to afcertain the longitude by 

 fhe obfervation of diftances of the moon from 

 the fun, or from a ftar. 



I am lorry that this valuable inftrument, al- 

 though extremely eafy to be ufed, is as yet little 

 known. Each of our officers had one, which in 

 the eourfe of the voyage became an inftrument 

 to be depended on in the hands of all. 



An obferver, of any experience, may afcertain 

 the longitude within two or three myriameters. 

 We have rcafon to hope that in proportion as 

 the lunar tables fhall acquire greater perfection, 

 the calculation of the longitudes from thefe 

 ubfervations will be flill much nearer the truth. 



The plants which I had collected at Tene- 

 riffe, although quite dry at the time of my 

 departure, had, while we had remained under 

 the tropics, become covered with a very thick 

 mildew, which was attached to the under part of 

 the leaves, where, as is well known, the ab- 

 sorbent pores are extremely numerous ; and my 

 Vjftiotvs had been greatly damaged. 



The water kept in a ftatc of difTolution by the 



air, by means of the direct heat of the fun, is in 



n fea, between the tropics, fo much more 



abundant than that with which the air can be 



load,cd 





