Positions determined by the Astronomical Obsei~vations of 
Ali Bey. 
Ali Bey determined the longitudes in 
the annexed table, by alternate observa- 
tions of the chronometrical differences 
of the lunar distances to the sun and 
stars, and of the eclipses of the satellites 
of Jupiter. The longitudes of Tangier 
and Fez are also compared with the re- 
sults obtained from a calculation of two 
eclipses of the sun, which our traveller 
observed in those towns — observations 
which were published in the Comzoissance 
des Terns, at Paris, and in the Nautical 
Almanac of the Isla de Leon, in Spain. 
The latitudes are the result of a great 
number of observations of the passage of 
the sun, and some circumpolar stars, over 
the meridian. 
Almost all these observations were 
made by means of an entire reflecting cir- 
cle of ten inches diameter, with four ver- 
niers, mounted on a stand, made in Lon- 
don, by Trougliton, an achromatic teles- 
cope, of 3i feet, by Dollond, a chrono- 
meter, by Brooksbanks, and another by 
Pennington. 
Although the positions of Alcassar and Mequinez are determined solely by the gecdesical 
estimates of Ali Bey, they may nevertheless be regarded as sufficiently exact, considering 
their very trifling distance from geographical points astronomically determined. 
The original observations, and the calculations, of Ali Bey, will be inserted and discussed 
in the scientific part of his travels, which will appear after the publication of the historical 
and descriptive part. 
The other points, in the routes of Ali Bey, are determined by his geodesical estimates, 
after a greatly approximated measurement of the angles of the rhumbs to the compass, as 
also of the length of the lines, made by numerous comparisons of the time with the rate of 
march of his caravans; and we possess nine route maps, made from day to day by Ali Bey, 
on a large scale, containing the development of the lines travelled over by him, in the king- 
dom of Morocco, and marked on this map. 
The chain of the mountains ot Atlas was seen by Ali Bey from Morocco, and along the 
road from Fez to Ouschda. We hence ascertain its direction between those two extremities 
of the empire. The rest of the chain is traced, according to information given to our tra- 
veller by natives of the country. These mountains are covered with perpetual snow. 
The other points in the map arc marked, in conformity to a great number of notices ob- 
tained from the inhabitants of the country by Ali Bey; and we have several sketches of his, 
which, by means of right lines, forming triangles with known points, mark their site and re- 
spective distances, in days' journeys and hours. 
The rivers flowing south from the mountains of Atlas enter the Sahhara, or Great De- 
sert. It is evident that they do not fall into any known sea, since they cannot return toward 
the Mediterranean, on account of the obstacle formed by that very chain; and, on the other 
hand, we know pretty nearly the source of the waters which Africa pours into the Atlantic 
ocean. It is said these rivers lose themselves in lakes in the midst of the desert. This must 
be the case; but until, the fact is ascertained, we shall merely indicate by points the extre- 
mity of their course. 
The projection of the coasts is marked according to the spherical map of that enlightened 
Spanish mariner, Mr. Varela: it is the best that we know; out the points are adjusted with 
reference to the geographical positions determined by Ali Bey, which, by the circumstances 
of the observations, appeared to us to deserve the preference. 
An h before a vowel, in the proper names, must be gently aspirated, as in the word hero: 
when there are two hh, they must be strongly aspirated, like the German ch. 
Geographical Positions determined by the 
Astronomical Observations of Ali Bey. 
Lbngitudl 
North 
west of the ob- 
Latitude. 
servatory at 
Oreenwich. 
~~o ~, ~ 
7~~t ~ 
Tangier, 
35 47 54 
5 53 45 
Laraisch, - 
35 13 15 
6 t 30 
Alcassar, 
35 1 10 
5 49 30 
Wazen, 
34 42 29 
Ouschda, 
34 41) 54 
1 47 45 
Teza, 
34 9 32 
3 40 0 
FEZ, - 
34 6 3 
4 58 15 
Rabat, 
34 4 27 
6 37 15 
Mequinez, 
35 58 30 
5 30 0 
Darbeida, - 
33 37 40 
7 29 45 
Azamor, 
33 18 46 
8 4 0 
MOROCCO, - 
31 37 31 
7 35 30 
Souera or Mogador, 
31 32 40 
9 35 30 
