PORTION OF THE COSMOS. NEBULJ5. 247 



resting on its summit. We shall see presently that the 

 nubeculse of the southern heavens, after having long been 

 noticed but without receiving any name, as navigation ex- 

 tended and commercial routes became more frequented, 

 gradually obtained names derived from those routes. 



The frequent navigation of the Indian sea adjacent to the 

 shores of Eastern Africa, especially from, the time of the 

 Ptolemies and in the voyages in which advantage was taken 

 of the Monsoons, first made navigators acquainted with the 

 constellations near the southern pole. As has been already 

 remarked, it is among the Arabians that we find as early as 

 the middle of the tenth century, a name for the larger of 

 the Magellanic clouds which Ideler has identified with the 

 (white) Ox, el-bakar, of the celebrated astronomer Dervish 

 Abdurrahman Sufi of Rai, a town in the Persian Irak. In 

 the ' ( Introduction to the Knowledge of the Starry Heavens/' 

 written at the -Court of the Sultans of the Dynasty of the 

 Buyides, he says : " Below the feet of Suhel" (it is ex- 

 pressly the Suhel of Ptolemy, Canopus, which is here 

 meant, although the Arabian astronomers also gave the name 

 of ' Suhel/ to several other large stars in the constellation of 

 " el Sefiua" or the Ship), "there is a white patch, which is 

 not seen either in Irak/' (in the region of Bagdad), "nor in 

 Nedschd," (Nedjed, the northern and more mountainous part 

 of Arabia), "but is seen in southern Tehama, between 

 Mecca and the point of Yemen, along the shore of the 

 Red Sea" ( 43 9). The position of the "White Ox" rela- 

 tively to Canopus is here assigned with sufficient accuracy for 

 the unassisted eye ; for the Eight Ascension of Canopus is 

 6 h 20 m , and the eastern margin of the larger Magellanic 

 cloud is in 6 h O in Right Ascension. The- visibility of 



Q 2 



