History of Astronomij for the Year 1806. 235 



the Latitude at Sea by Altitudes taken out of the Meridian, 

 and. the Longitude by an Altitude of the Moon in several 

 Cases." 36 pages 4to. He shows the inconveniences into 

 which we may fall by employing the method of d'Awes, and 

 the precautions which may be taken to avoid them. lie 

 was not acquainted with the grand work with which 

 M. Mendoza was occupied. 



With respect to the method of the longitudes, it is long 

 since Lemonnier, Pingre, and myself, showed its utility; 

 it is specially indicated in page 68 of my Abregc de Navi- 

 gation, as being able to simplify considerably the method of 

 the longitudes by means of the horary tables I have pub- 

 lished with this abridgment. 



The new lunar tables of M. Burg serve for calculating the 

 observations of longitudes made in the voyage of New Hol- 

 land ; and Michael Lalande has calculated for this purpose 

 several observations of the moon at the meridian. 



It remains to recalculate all the observations made in the 

 three voyages of Cook, because they have been compared 

 with the lunar tables we had at that time, and v\ hich were 

 not exact enough to hold the place of corresponding ob- 

 servations. 



Geography has this year made new procrross. Munn-o 

 Park has written from Tonibuctoo on the coast of Africa. 

 A report had been spread of his death. His return will 

 make us acquainted with some curious circumstances re-' 

 specting these unknown countries. 



The vessels the Navesda and the Neva, which left Crou- 

 stadt on the 7lh of August 1S03, uv,der the orders of cap- 

 tain Krusenstcrn, returned on the 4lh and linli of August 

 1806, after having sailed round the world. This is lixi first 

 circunmavigation of the Russians. M. Horner iriade se- 

 veral imporlant observations for geography upon the coast 

 of Tartary. 'I'here are several of them in the Journal of 

 Gotha for September 1806, in which baron Zach continues 

 to publish every thing interesting in asironomv ; another 

 proof how necessary it is for an astronomer to be accjuaintcd 

 with German. . , 



M. Nisiui:usk)> astronomer lo the l?etcrsburgh Academv, 



has- 



