VOL. LXXV.j 1'HILOSOPHICAL TRANSACTIONS. OCJ 1 



An Opening in the Heavens. — Some parts of our system indeed seem already 

 to have sustained greater ravages of time than others, if this way of expressing 

 myself may be allowed ; for instance, in the body of the Scorpion is an opening, 

 or hole, which is probably owing to this cause. I found it while gaging in the 

 parallel from 112 to 114 degrees of north polar distance. As I approached the 

 milky way, the gages had been gradually running up from 9.7 to 1 7.1 ; when, 

 all of a sudden, they fell down to nothing, a very few pretty large stars excepted, 

 which made them show 0.5, 0.7, 1.1, 1.4, 1.8 ; after which they again rose to 

 4.7, 13.5, 20.3, and soon after to 41.1. This opening is at least 4 degrees 

 broad, but its height I have not yet ascertained. It is remarkable, that the 80 

 Nebuleuse sans etoiles of the Connoissances des Temps, which is one of the 

 richest and most compressed clusters of small stars I remember to have seen, is 

 situated just on the western border of it, and would almost authorize a suspicion 

 that the stars of which it is composed were collected from that place, and had left 

 the vacancy. What adds not a little to this surmise is, that the same phenomenon 

 is once more repeated with the 4th cluster of stars of the Connoissance des Temps; 

 which is also on the western border of another vacancy, and has a small, minia- 

 ture cluster, or easily resolvable nebula of about 24- minutes in diameter, north 

 following it, at no very great distance. 



Phenomena at the Poles of our Nebula. — I ought to observe, that there is a 

 remarkable purity or clearness in the heavens when we look out of our stratum at 

 the sides, that is, towards Leo, Virgo, and Coma Berenices, on one hand, and 

 towards Cetus on the other ; whereas the ground of the heavens becomes troubled 

 as we approach towards the length or height of it. It was a good while before I 

 could trace the cause of these phenomena ; but since I have been acquainted with 

 the shape of our system, it is plain that these troubled appearances, when we ap- 

 proach to the sides, are easily to be explained by ascribing them to some of the 

 distant, straggling stars, that yield hardly light enough to be distinguished. And 

 I have indeed often experienced this to be actually the cause, by examining these 

 troubled spots for a long while together, when, at last, I generally perceived the 

 stars which occasioned them. But when we look towards the poles of our system, 

 where the visual ray does not graze along the side, the straggling stars of course 

 will be very few in number ; and therefore the ground of the heavens will assume 

 that purity which I have always observed to take place in those regions. 



Enumeration of very compound Nebulce or Milky-Ways. — As we are used to 

 call the appearance of the heavens, where it is surrounded with a bright zone, the 

 milky-way, it may not be amiss to point out some other very remarkable nebulae 

 which cannot well be less, but are probably much larger than our own system ; 

 and being also extended, the inhabitants of the planets that attend the stars which 



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