TRANSACTIONS OF THE SECTIONS. 17 
The first observation of Eunomia was made with the parallel wire micrometer, 
and power 110; all others with the ring micrometer, and power 84 of the Hartwell 
Equatorial. The comparison stars employed were as in the annexed list :— 
Mean R. A. | Mean P. D. 
Authority. Mag. 1860. 1860. 
hm s ow 
Oeltzen Arg. 33 & 34=9 Lalande (weight 3). | 89 | 0 3 16°86) 105 13 43:0 
Weisse 0°227. 9 | 013 40°42 | 104 24 31°4 
11 Ceti; Madler’s Bradley 36 ; 78 Robinson. 78 | 0 22 44:01} 91 53 209 
Weisse 0°592. 9} 0 34 46°05} 90 47 32°5 
4704 Robinson. 7 | 21 30 22:25] 91 0 563 
24 Aquarii; Miadler’s Bradley 2°816. 7 | 21 32 1844/9041 13 
Weisse xxi. 916=42598 Lalande (weight 4). 9 | 21 38 11°65] 90 51 2-9 
The following magnitudes have been carefully estimated; generally, by com- 
parison with apparently similar objects in the nearest variable star-map then in 
course of construction :— 
Victoria, 1860, April 3...... 10°5 mag. | Eunomia, Sept. 1, 8-2 ; Sept. 4,8°6 ; Sept. 7, 8°3. 
Thetis By PS il Peace 10°5 ,, | Olympia, Sept. 25, 9°6; Oct. 3, 10°2. 
Metis ps Sept. Bes sees 9:0 ,, | Amphitrite, Oct. 3, 9-0. 
Thalia, Sept. 7, 11:0; Sept. 10, 11:2; Sept. 13, 11:0; Sept. 25,11°0; Oct. 3, 11:5. 
The preceding observations of minor planets were the last made by Mr. Pogson 
before leaving England for Madras in January 1861; it was his intention to reduce 
them speedily, and to send them to me from Malta or Alexandria; but, as antici- 
pated, the inconveniences of a sea-yoyage prevented him from fulfilling his design, 
and the pressure of official duties in his new position has not permitted him to 
attend to his former unfinished pursuits until recently. 
On the Excentricity of the Earth, and the Method of finding the Coordinates 
of its Centre of Gravity. By W. Oattsy, F.GS. 
On the probable Origin of the Heliocentric Theory. By J. Scuvarcz. 
The author traced the origin of the Copernican system to Pythagoras, through 
Aristarchus the Samian and Archimedes of Syracuse. 
On Autographs of the Sun, By the Rey. Professor Setwyn, 
The author showed several “ autographs of the sun,” taken with his “heliauto« 
graph” by Mr. Titterton, photographer, Ely, which consists of a camera and in- 
stantaneous slide by Dallmeyer, attached to a refractor of 2$ inches aperture by 
Dollond; the principle being the same as that of the instrument made, at the 
suggestion of Sir J. Herschel, for the Kew Observatory. The autographs are of 
July 25,°26, 28, 29, 31; August 1, 2, and August 4, 10.15 a.m. and 11.30 a.m. (a 
series of bright days coincident with a large group of spots); August 19, 20, 23 
and 25, where the same group reappears, much diminished; September 19, 23, 26, 
30, Oct. 1, in which is seen a group of 118,000 miles in length. On the 23rd 
three autographs were taken, two of them with the edge of the sun in the centre of 
the Aap goes plate, showing that the diminution of light towards the edges of 
the disk is a real phenomenon, and not wholly due to the camera. In the two of 
the 4th of August, where the great spot (20,000 miles in diameter) appears on the 
edge, a very distinct notch is seen, and the sun appears to give strong evidence that 
the spots are cavities ; but eye observations and measurements by the Rey. F. How- 
lett, and others, tend to show that this evidence is not conclusive, for there was 
still a remaining portion of photosphere between the spot and the edge. The phe- 
nomena shown in these autographs appear to confirm the views of Sir J. Herschel, 
eT tes two parallel regions of the sun where the spots appear, are like the tro- 
