S32 COSMOS. 



nificcnt effulgence. The light emanating from this region is 

 PO extraordinary that Captain Jacob, an accurate observer, 

 and a resident in the tropical parts of India, remarks, ent irely 

 in harmony with my prolonged experience : " Such is the 

 general blaze from that part of the sky, that a person is 

 immediately made aware of its having risen above the 

 horizon, though he should not be at the time looking at the 

 heavens, by the increase of general illumination of the 

 atmosphere, resembling the effect of the young Moon." TO 



The nebula, in the midst of which lies the star 17 Argus, 

 which has become so celebrated for the alterations observed 

 in the intensity of its light, covers a space of more than ^ths 

 of a square degree. 71 The nebula itself, which is divided 

 into many unsymmetrical masses of unequal luminous inten- 

 sity, nowhere exhibits the speckled, granular appearance which 

 admits of the assumption of its resolvability. It incloses a sin- 

 gularly shaped, oval vacancy, covered with a faint glimmer of 

 light. A fine delineation of the entire appearance, the result of 

 two months 1 measurements, is given in Sir John Herschel's Ob- 

 servations at the Cape. n This observer determined no less than 

 1.216 positions of stars, mostly from the fourteenth to the six- 

 teenth magnitudes, in the nebula of / Argus. These extend far 

 beyond the nebula into the Milky Way, where they stand 

 clearly forth on the deep black ground of the sky, and they 

 are probably, therefore, unconnected with, and far removed 

 from, the nebula itself. The whole contiguous portion of the 

 Milky Way is, moreover, so rich in stars (not clusters), that 



70 Transact, of the Royal Society of Edinburgh, vol. xvi. 

 18 '9, part iv. p. 445. 



71 Cosmos, vcl. iii. pp. 240-243. 



78 Olscrv. at the Cape, 70-00, pi. ix. Outlines, 887, 

 pi. iv. n-. 2. 



