560 Chronicles of Science. [ Oct., 
make use of apparatus comparable in power and accuracy with that 
which Mr. Huggins has applied to spectroscopic analysis. We 
should then be better able to form an opinion of the value of his 
researches. At present it is impossible to avoid entertaiming a 
suspicion that the apparatus employed by him is not powerful 
enough for researches of such extreme delicacy as those m which 
he is engaged. 
Mr. Brothers, to whom we owe the valuable catalogue of double 
stars, published by the Manchester Literary and Philosophical 
Society, supplies a paper on the name of the star ¢ Scorpu. In 
Flamsteed’s catalogue this star is called 51 Libre. This was 
undoubtedly a blunder on Flamsteed’s part, as the star belongs to 
the set of stars which form the northern claw of the Scorpion. 
But we doubt very much whether it would now be wise to attempt 
to alter Flamsteed’s nomenclature. Mr. Brothers thinks it would, 
and he quotes Mr. Dawes’s opinion in favour of the change. “ Libra 
already has three £’s,” says Dawes, “ and without this star Scorpio 
has no £ at all.” But there is, in truth, no particular force in this 
reasoning. Pegasus has no 3 (Bayer’s 3 Pegasi being also called 
« Andromede) and Auriga has no y (Bayer’s y Aurige being also 
called 6 Tauri); yet no inconvenience results from either defect.. 
On the other hand Flamsteed’s nomenclature has been so generally 
adopted in scientific treatises on the stars, that inconvenience would 
follow if a star to which he had assigned a number under one 
constellation, were to be included in another. The nomenclature 
suggested by Mr. Brothers, “¢ Scorpii (= FI. 51 Libre)” is far too 
clumsy for general use. 
Mr. Brothers complains with some justice of the use made by 
Mr. Chambers of the catalogue mentioned in the preceding 
paragraph. . 
Major Drayson supplies an interesting paper on the longitudes 
assigned to fixed stars by Ptolemy. He is disposed to attribute 
the uniform error of about 1°, noticed in Ptolemy’s longitudes, to 
that astronomer’s ignorance of the laws of refraction. Assuming 
that Ptolemy fixed the positions of stars by a reference to the moon, 
and that he determined the position of the moon with reference to 
the sun by observations made when the moon was near the zenith 
and the sun on the horizon, we obtain an error of about 1° (one- 
half due to the apparent diminution of the moon’s distance from 
the sun, and the other due to the apparent diminution of the stars’ 
distance from the moon). We believe, however, that the opinion of 
Delambre, that Ptolemy formed his catalogue from that of Hippar- 
chus by applying a correction for precession, and that the correction 
was 1° in 100 years, instead of the true value 50':1, is far more 
probable than Captain Drayson’s. ‘The uniformity of the error 
suggests that some such explanation as Delambre’s 1s the true one. 
