684 



1735, had no knowledge when they left Europe? 

 of the observations made at Surinam, on the 

 regularity of the atmospheric tides ; MM. 

 Bouguer and Condamine attributed the disco- 

 very of this regularity to one of their col- 

 leagues^ M. Godin. " I also made some obser- 

 vation, says la Condamine # , on the barometer, 

 in the year 1741, at first with M. Godin, and 

 afterwards alone, in order to confirm M. Go- 

 din's remark, who first perceived several daily 

 and periodical variations. I found the baro- 

 meter at its greatest height towards nine in the 

 morning, and at its least towards three in the 

 afternoon ; the mean difference (at Quito) was 

 II of a line." M. de la Condamine, in his Re- 

 lation du Voyage d V Ama%one 3 returns to the 

 same subject. " M. Godin," he says, " remarked 

 that the variations of the barometer (in the 

 equinoxial zone,) alternate very regularly ; one 

 experiment consequently suffices to judge of the 

 mean barometric height -f-." 



* V oyage to the Equator, p. 50 and 109. Bouguer, who 

 speaks with the same brevity of the observation of Godin, 

 adds, that the variations of the barometer at the equator, 

 are two to three lines at the seashore, and about one line at 

 Quito. {Figure de la Terre, p. 39). We see by the work 

 of M. Thibault de Chanvalon, that Bouguer's manuscripts 

 contained a great number of unpublished horary observations. 

 Voyage a la Martinique, p. 135 (22). 



t Voyage a la Riv. des Amaz., p. 23. I have founded on 



