in the Mountains of the Moon. 225 



Of these Mountains of the Moon, the one extre- 

 mity is in . . . . 57' E. long. 12° 30' S. lat. 

 And the other is in . . . 67° ... 12° 30' ... 



And lastly, in the seventh Chapter of the same Book,* the 

 following positions are given : — 



The mouth of the river Rhaptus, . 72° 0' E. long. 7° 0' 8. lat. 

 Rhapta, the capital of Barbaria, at a short dis- 

 tance from the sea, . . . 71° 0' ... 7° 0' ... 

 Cape Rhaptum, . . . 73° 50' . . . 8° 36' ... 



Notwithstanding the minuteness with which these parti- 

 culars of latitude and longitude are specified, it is not to be 

 imagined that they are the results of actual observations, 

 even if only roughly made. So far from this being the case, 

 v/e have the express authority of Ptolemy himself t to show 

 that they are nothing more than general approximations, such 

 as every one w^ho constructs a map from imperfect oral infor- 

 mation has to be satisfied vpith ; and it appears, indeed,J that 

 the " Tables" from which the foregoing passages have been 

 extracted, are merely of the nature of an index to the maps 

 which were at the same time constructed by the geographer.§ 

 By this it is not intended that the maps bearing the name of 

 Agathodsemon, which are inserted in the several editions of 

 the Geography, were actually delineated under Ptolemy's di- 

 rection ; since no proof exists of this being the case, though 

 it is far from improbable. All that is meant is, that Ptole- 

 my formed his tables of latitude and longitude from maps 

 which had previously been constructed by him, as maps are 

 constructed by geographers now-a-days, " from the best au- 

 thorities ;" and it is only by restoring the particulars recorded 

 in those tables to their positions on the map, and placing them 

 before our eyes in that shape, that we shall be enabled to 

 estimate them at their true value. Accordingly, in the ac- 

 companying Plate (PI. IV., fig. 1.) is represented Ptolemy's (or 

 Agathodaemon's) fourth Table or Map of Africa, as the same 

 is given in Bertius's edition of the great geographer's work.1I 

 This map is doubtless subject to errors, arising from cor- 



* P. 112 (Edit. Rertii, p. 128). 



t Ijib. i., passim. | Lib. vii., viii. 



§ Pp. 200, 201 (Edit. Bertii, p. 234, 235). 



^ Theatrum Oeograpfiia: Vvterit (fol. Amstelodami, 1G18). 



