108 Chronicles of Science. | Jan. 
result of Sir John Herschel’s indefatigable research is published to 
the world. a 
Stellar parallax, in the hands of M. Kruger of Bonn, has yielded 
results for the stars 21,258 of Lalande’s Catalogue, and 17,415 of 
Oltzen’s Zones. To the former he assigns a parallax of 0-260, with 
a probable error of + 0":02, and to the latter a parallax of 0-247, 
with a probable error of 0-021. From these determinations we must 
infer that these two stars, both telescopic, are nearer to us than either 
Capella, Polaris, Arcturus, or Sirius. 
Of the various fields of active work open to amateur astronomers, 
none are so promising as observations on variable stars. The task is 
a hard one, and requires unquestionably great patience and perseverance, 
but to those endued with these gifts a fine future is open. The number 
of known variables is steadily increasing, and now exceeds one hundred, 
to which the indefatigable Pogson of Madras has added another 
member within the last few months. He designates it U. Scorpii, and its 
place for 1860 is R.A. 16h. 14m. 26-6s., 3 17° 33’ 36” S. It is likely 
to prove an object of particular interest, having been found by the dis- 
coverer to pass through three entire magnitudes in little more than 
one month, a rapidity of change only known to be equalled by three 
other stars. 
Astronomical photography, in the able hands of Mr. De La Rue and 
the Kew observers, is making steady progress, but nothing has occurred 
during the period over which our survey extends, calling for particular 
notice. 
Solar photometry has recently received important development in 
America under the ingenious manipulation of Mr. Alvan Clarke, the 
well-known optician. A well of adequate depth not being at his dis- 
posal, he made use of a horizontal gallery 230 feet long, through which 
the sun’s rays, on a very clear bright day, were made to pass by the 
agency of a prism and mirror to obtain the required reflection. He 
employed a lens 1. of an inch focal length, and thus reduced the sun’s 
diameter 93,840 times, when it presented a brilliancy “which was 
estimated at scarcely equal to « Lyrz.” Mr. Clarke considers that ten 
per cent. loss will be a reasonable allowance for the reflections ; and 
weighing some comparisons of « Lyre without the lens, he gives it as 
the final result that the sun would have to be removed 103,224 times 
its present distance, for it to appear no brighter than the star referred to. 
No review of this character can be complete without a chronicle of 
literary intelligence, and we shall therefore glance cursorily at the 
performances of 1863 and the promises of 1864, which can scarcely 
fail to be useful and interesting. An important reprint has been issued 
in France—a work by the celebrated astronomical king, Alphonso X. 
of Castile. It is divided into sixteen parts, commencing with a cata- 
logue of the fixed stars. The royal author then treats of the apparatus 
and instruments necessary for observing the stars and estrellas movediros, 
or planets. Speaking of the constellations, he says of Ursa Major :— 
“Some astronomers have taken it for a wain with its pole, others say 
that it has the form of an animal which might as well be a lion, a 
