328 The Construction of the Heavens. (July, 
irresolvable nebulosity.” This reasoning is complete against 
Struve’s inferences as based on Struve’s assumptions. It is 
not, however, the less certain that irresolvable nebulosity 
does not necessarily imply that the objeéts producing it 
‘stretch out beyond the utmost reach of the telescope,” as 
is proved by the irresolvable nebulosity discovered by Sir 
John Herschel himself within the bounds of the Magellanic 
clouds. 
I shall treat very briefly of the results to which I have 
been led by my own researches into the subject of the con- 
stitution of the heavens, because they have been fully pre- 
sented elsewhere.* 
The purposes I have had in view throughout my inquiries 
have been two—First, to proceed in perfect independence of 
all preconceived theories—to inquire how the stars and 
nebule are spread in space, how they differ in magnitude or 
constitution, and what laws govern their changes and move- 
ments, instead of adopting any assumptions on these points 
as bases for reasoning; and, secondly, to endeavour in every 
case to render palpable to the eye the relations which have 
hitherto been presented only in elaborate catalogues or in 
tables of statistics. It is to subserve the latter purpose, 
which is obviously associated most intimately with the 
former, that I have adopted the methcod of equal-surface 
charting. In dealing with the proper motions of the stars 
I have drawn from each star an arrow whose length and 
direction shall indicate the rate and direction of the star’s 
proper motion. I venture to believe that by these and other 
contrivances I have been enabled to exhibit the above- 
mentioned relations altogether more intelligibly than has 
hitherto been the case, and that laws hitherto unrecognised 
have thus been brought to light. 
In the first place, 1 have been able to showthat the stars, 
down even to the sixth magnitude only, are markedly 
crowded upon the milky way, and that, moreover, there are 
two rich stellar regions (as respects these lucid stars), 
nearly opposite each other, one covering the constellations 
Cepheus, Cygnus, Cassiopeia, and Draco, the other occu- 
pying the space included between the heel of Argo, Crux, 
and the Greater Dog. The following table (shortened from 
one in my ‘‘ Essays”) indicates the numerical relations 
involved, the numbers in the second column representing 
the total number which would be visible if the whole 
* | may be permitted to point out that the researches themselves, as origi- 
nally submitted to the Royal Astronomical Society, are contained in my 
«Essays on Astronomy.” 
