100 
POPULAR SCIENCE REVIEW. 
104 y. -jg ; Moller, from Faye’s comet, 104 7 . y 9 ; Von Asten, from that of Encke, 
1 
1047 - 61 * 
Saturn has been very unfavourably situated for English observers ; but 
the position of the satellites has been compared with Marth’s ephemerides 
by Mr. Christie at Greenwich.— Le Verrier has compared his theory of this 
planet with the observations of the last thirty-two years, and finds the result 
satisfactory, some slight discrepancies being probably due to the varying 
aspect of the ring. 
Uranus . — Professor Newcomb, who is in charge of the great achro- 
matic at the Washington Observatory, of 26 inches’ aperture, has made a 
special study of the satellites of this body during the early part of this year. 
He fully confirms Lassell’s opinion that there are only four, the orbits of 
which he finds nearly circular and in the same plane. The brighter 
satellites, Oberon and Titania , appeared in this noble instrument about equal 
to fourth magnitude stars with the naked eye ; the two inner ones he 
thinks the most difficult of well-known objects, but was surprised at the 
precision with which he could bisect them. They were pretty certainly 
discovered by Lassell, and have not been, he thinks, subsequently seen by 
any one except himself; they are claimed, however, by the Melbourne 
reflector. Sir W. Herschel’s outer satellites he pronounces non-existent. 
The feeble perturbation of these minute bodies by each other or by the far- 
distant sun in the immediate presence of their overpowering primary 
enables the mass of the latter to be ascertained with considerable exactness, 
and the Professor deduced a value of ^oo* The accurate focusing of the 
eye-piece was, however, disturbed by the differing colour of the redly 
illuminated micrometer webs and the greenish-yellow satellites, and this 
may somewhat affect the result. No markings were detected on the disc. 
It is believed that the two brighter satellites are within the grasp of the 
larger telescopes in England. 
Observatories and Instruments . — The Paris Observatory is now opened by 
Le Verrier’s orders three times a week in the evening, weather permitting, 
and two large telescopes are placed at the disposal of visitors provided with 
letters of admission, obtained by application to the secretary. This is a 
move of the most commendable nature, and an example which we should 
do well to follow. The arrangement of our public observatories might 
not admit, generally speaking, of such an interruption ; but it might be 
worthy of consideration whether observatories for popular and educational 
purposes might not be established in our larger cities, provided with 
sufficient instruments and attendants, the expenses of which might be met 
by subscriptions and entrance charges. — We regret to find that Mr. Hind’s 
observatory at Twickenham, the 7-inch Dollond achromatic in which did 
such excellent service at Mr. Bishop’s in Regent’s Park, is to be dismantled, 
and the instruments presented to the Royal Observatory at Naples. — 
Winnecke at Strasburg describes a new orbit-sweeper, and announces the 
commencement of a review of nebulae. — The observatory of the Rev. H. C. 
Key, at Stretton, near Hereford, is now in a high state of efficiency, being 
provided with two 18-inch silvered glass specula, perfect to the edge, one 
of which is equatorially mounted and driven by clockwork. There is a 
