NEBULA. 29 



The actual northern maximum lies, therefore, between 

 12h. and 13h., v«ry near the north galactic pole. Beyond 

 that point, between 15h. and 16h. toward Hercules, the dim- 

 inution is so rapid that the number 130 is followed directly 

 by 40. 



The southern hemisphere presents not only a smaller num- 

 ber, but a far more regular distribution of nebula3. Regions 

 destitute of nebulse here frequently alternate with sporadic 

 nebulae. An actual local accumulation, more dense, indeed, 

 than the nebulous region of Virgo in the northern heavens, 

 occurs only in the Great Magellanic Cloud, which alone con- 

 tains as many as 300 nebulse. The immediate polar regions 

 of both hemispheres are poor in nebulse, and to a distance of 

 15° the Southern Pole is still more so than the Northern, in 

 the ratio of 4 to 7. The present North Pole exhibits a small 

 nebula, only 5 minutes' distance from it, while a similar neb- 

 ulous body, which Sir John Herschel has aptly named Nebula 

 polarissima Australis (No. 3176 of his Cape Catalogue, R. 

 A. 9h. 27m. 56s. ; N. P. D. 179° 34' 14"), is situated at a dis- 

 tance of 25 minutes from the South Pole. This paucity of 

 stars in the south polar region, and the absence of any pole- 

 star visible to the naked eye, were made the subject of bitter 

 lamentation by Amerigo Vespucci and Vicente Yaiiez Pinzon, 

 when, at the close of the fifteenth century, they penetrated 

 far beyond the equator to Cape San Augustin, and when the 

 former even expressed the erroneous opinion that the fine 

 passage of Dante, "Jo mi volsi a man destra, e posi mente 



" and the four stars described as " non viste mai 



fuorcK alia prima gente,"" referred to antarctic polar stars. ^ 



* Humboldt, Examen Critique de VHist. de la Geographic, torn, iv., p. 

 319. The Venetian Cadamosto (more properly called Alvise da Ca da 

 Mosto) first turned his attention to the discovery of the position of a 

 south polar star when in company with Antoniotto Usodimare, at the 

 mouth of the Senegal, in 3 454, in the course of one of the many voy- 

 ages in which the Portuguese engaged, under the auspices of the In- 

 fante Don Henrique, for the purpose of advancing along the western 

 shores of Africa, beyond the equator. " While I still see the north 

 polar star," he writes, being then in about 13° north latitude, " I can 

 not see the south polar star itself, but the constellation which I perceivt» 

 toward the south is the Carro del ostro (wagon of the south). (Aloysit 

 Cadam. Navig., cap. 43, p. 32 ; Ramusio, Ddle Navtgationi et Viaggi, 

 vol. i., p. 107.) Could he have traced the figure of a wagon among 

 some of the larger stars of the constellation Argo ? The idea that both 

 poles had a constellation of the " Wain" or wagon appears to have been 

 so universal in that age, that there is a drawing of a constellation per- 

 fectly similar to Ursa Minor, supposed to have been seen by Cadamosto, 

 both in the Itinerarium Portugallense, 1508, fol. 23, b, and in Grynaeua 



