Notices respecting New Books. 235 



down to the eleventh inclusive ; and a table is given in which are 

 exhibited the numbers of all the stars of the several magnitudes 

 occurring in the registered gauges, distributed in the respective zones 

 of galactic polar distance. The following are the results : — 



" On a general view of the table it appears that the tendency to 

 greater frequency, or the increase of density in respect of statistical 

 distribution, in approaching the Milky Way, is quite imperceptible 

 among stars of a higher magnitude than the 8th, and except on the 

 very verge of the Milky Way itself, stars of the 8th magnitude can 

 hardly be said to participate in the general law of increase. For the 

 9th and 10th, the increase, though unequivocally indicated over a 

 zone extending at least 30° on either side of the Milky Way, is by 

 no means striking. It is with the 11th magnitude that it first be- 

 comes conspicuous, though still of small amount when compared 

 with that which prevails among the mass of stars of magnitudes 

 inferior to the 11th, which constitute sixteen-seventeenths of the 

 totality of stars within 30° on either side of the galactic circle. 



"Two conclusions seem to follow inevitably from this; viz. — 1st, 

 that the large stars are really nearer to us (taken en masse, and with- 

 out denying individual exceptions) than the smaller ones . . . . ; 2nd, 

 that the depth at which our system is plunged in the sidereal stratum 

 constituting the galaxy, reckoning from the southern surface or 

 limit of that stratum, is about equal to that distance which, on a 

 general average, corresponds to the light of a star of the 9th or 10th 

 magnitude, and certainly does not exceed that corresponding to the 

 11th."— P. 383. 



The 2nd Section of this chapter contains a minute and exceedingly 

 interesting description of the general and telescopic appearance of 

 the Milky Way — too long, however, to be extracted here in extenso, 

 and scarcely susceptible of abridgement. We must make room for 

 two or three paragraphs. 



" Immediately after the contraction between X Centauri and 2 Cruris 

 the Milky Way suddenly expands so as to include the southern half 

 of the cross and the northern portion of Musca, whence it proceeds 

 to fl Centauri, embracing in this wide expansion that singular vacuity 

 on the south following side of the cross, called the ' Coal-sack,' a 

 pear-shaped oval, whose greatest length is about 8°, and breadth 5°, 

 the longer axis being nearly parallel to the line joining a and /3 Crucis, 

 which line is very nearly a tangent to the north-preceding portion 

 of its circumference. As this is always regarded by voyagers and 

 travellers as one of the most conspicuous features of the southern 

 sky, it may not be irrelevant to state a few particulars as to its tele- 

 scopic constitution. It is by no means entirely devoid of stars, the 

 lowest gauges being 9 and 7, and no blank fields being specified as 

 occurring in it. The cluster of telescopic stars h. 3407 is actually 

 contained within its area ; and even in the middle of its extent 

 gauges of 29 and 48 stars are noted. Its striking blackness is, 

 therefore, by no means owing to an absolute want of telescopic stars, 

 but rather to its contrast with the very rich portion of the Milky 

 Way adjacent, where the gauges run up to 98, 100, 120, and even 



R2 



