1870.] Astronomy. 253 



13 seconds, he remarks that, so far back as April, 1869, he pointed 

 out the ratio of the probable errors arising from this cause in the 

 transits of 1874 and 1882. 



In a paper on the same subject, Mr. Proctor points out that from 

 Mr. Stone's observations upon the transit of November, 1868, it can 

 be shown how the discrepancy of 13 seconds can be reduced to one 

 of only the tenth of a second. 



Mr. Birt describes the spots and markings on the floor of the 

 lunar crater Plato. 



The Assistant-Secretary, Mr. Williams, has just completed the 

 translation of the Chinese records of comets observed from b.c. 613 

 to a.d. 1640. Some of the observations will probably bear im- 

 portant fruit, since no well-authenticated accounts of comets, seen 

 so long ago, exist elsewhere. 



Mr. Browning supplies a most interesting paper on a change in 

 the colour' of the equatorial belt of Jupiter. During the month of 

 October last he noticed that this belt, which is usually the brightest 

 part of Jupiter's disc, exhibited a strong greenish yellow colour, and 

 was darker than the bright belts north and south of it. Other 

 observers, using Browning's reflecting telescopes, have observed 

 similar appearances. Indeed, it is worthy of notice that, not only 

 these changes of colour, but the colours ordinarily present in the 

 discs of Jupiter and Saturn have been only seen distinctly with 

 reflectors. MM. De la Kue and Lassell, for example, have seen these 

 colours with their fine reflectors, whereas Dawes, with all his asto- 

 nishing powers of vision, and though he used refractors of exquisite 

 defining power, has not been able to recognize them clearly, if at all. 



Mr. Weston supplies an interesting note on the lunar Apennine 

 range and adjacent regions. 



Mr. Carrington describes his new Observatory at Churt, Surrey. 

 The principal telescope is an alt-azimuth, constructed on a new 

 principle, the horizontal axis being the effective optical axis. A 

 movable prism, placed outside the object-glass, reflects the object 

 along the tube. Thus the telescope need never be raised, and the 

 observer can remain always under cover. 



Mr. Proctor puts forward a new theory of the Milky Way. He 

 regards this sidereal group as forming a spiral of really small stars, 

 swayed into its present position by the attractions of the large stars 

 which are seen on the galaxy. 



Messrs. Airy and Simms have at length brought their new eye- 

 piece to its simplest and most perfect construction. By the mere 

 rotation of the eye-glass — which must be plano-convex — all the 

 effects of the flint-glass prisms described in our last Chronicle can 

 be obtained without any mischief to the optical performance of the 

 telescope. 



Mr. Proctor supplies a paper on the application of photography 



