190 
POPULAR SCIENCE REVIEW. 
Way as a ring of circular section — that is, as resembling in section an ordi- 
nary wire ring — one can understand many peculiarities of its structure 
which seem wholly opposed to either the disc or the flat-ring theory. For 
example, the great gap in the constellation Argo may be readily explained, 
and so also can the yet wider vacant space in the fainter branch where the 
ring is double. Mr. Proctor shows how, by assigning to the Milky Way a 
spiral figure, nearly all the principal peculiarities of the zone can be very 
fairly accounted for. 
The Sun's Corona. — Astronomers are already looking forward with 
interest to the total eclipse of next December, when they hope to solve the 
perplexing problem presented by the solar corona. Mr. Lockyer, in a paper 
communicated to the Royal Society, has expressed his continued adherence 
to the theory which explains the corona as due to the glare of our own 
atmosphere. In this way he gets over certain difficulties presented by the 
results of spectroscopic analysis as applied by himself to the chromosphere 
and prominences, and by the American observers to the corona. It may be 
questioned, however, whether these spectroscopic observations cannot be 
interpreted more simply. One point, at any rate, is obvious ; the corona is 
not a solar atmosphere : that it is, however, a solar appendage, can hardly, we 
think, be reasonably doubted. 
The November Meteors. — Observations made on these objects, last Novem- 
ber, have continued to come in from various far distant stations. They 
point conclusively to a well-marked spreading of the meteor system, as com- 
pared with the portion through which the earth passed in November 1868. 
In fact, from some observations made by Lieut. Tupman at Port Said, it 
would seem as though the width of the system had increased fully fourfold 
in the interval. The problem presented by the November meteors becomes 
more and more interesting, the more we consider the relations really 
involved in what has been discovered respecting the extent of the system. 
Mr. Carrington's new Observatory and Horizontal Alt- Azimuth. — Mr. 
Carrington, whose researches into solar physics must be familiar to all our 
astronomical readers, has just completed the construction of a new obser- 
vatory which presents several features of interest. The observatory is on 
the summit of a hill sixty feet high, but is itself sunk below the ground, 
“just peeping over the soil/’ Mr. Carrington has sunk a diy well, six feet 
in diameter, to the depth of forty feet, from the centre of the observatory, 
and with a horizontal shaft communicating with the south side of the hill, 
166 feet in length, closed with three doorwaj r s. This is chiefly meant for 
the clock, for Mr. Carrington is u determined to have one clock at least pro- 
perly mounted, at a position of invariable temperature, and in an air-tight 
case.” The principal telescope is an alt-azimuth, constructed on a new 
principle. Mr. Carrington has adopted Steinheil’s principle of making the 
horizontal axis the effective optical axis, by placing the object-glass at one 
end and the eye-piece at the other, with a prism outside the object-glass. 
The casting of the prism took over three months, but Messrs. Chance suc- 
ceeded at last. u It is some comfort,” remarks Mr. Carrington, u to think 
that never need the telescope be raised, only turned round, and the observer 
always under cover.” 
The Proper Motion of the Stars , and the Sun's Motion in Space. — Mr. 
