1868. | Astronomy. 509 
lation. The question here is not one of minute variations in 
subordinate features, which may or may not be attributable to dif- 
ferences of optical power in the instruments used by different 
observers, as in the case of the nebula in Orion, but of a total 
change of form and character—a complete subversion of all the 
greatest and most striking features—accompanied with an amount 
of relative movement between the star and the nebula, and of the 
brighter portions of the latter inter se, which reminds us more of 
the capricious changes of form and place in a cloud drifted by the 
wind, than of anything heretofore witnessed in the sidereal 
heavens.” 
Not less remarkable is the change which, according to Mr. 
Abbott’s diagrams, would seem to have taken place in the arrange- 
ment of the fixed stars which are strewn over the nebula. Sir 
John Herschel determined during 1834-7 the position of no less 
than 1,200 of these ; and during all the course of his observations 
never found reason to. suspect the situations of any of these to be 
variable inter se or with respect to the star 7. Mr. Abbott's 
drawing shows 150 stars of various magnitudes, and Sir J. Herschel 
has been unable to identify any one individual with any one in his 
catalogue. “What then,” he says, “are we to conclude? Not 
only the nebulous masses would appear to have drifted away from 
their situations in 1835, but the stars of the whole region over an 
area of nearly two-thirds of a square degree, including stars of the 
6th, 7th, and 8th magnitudes, to have either assumed new con- 
figurations inter se, or to have bodily fled away and given place to 
a new set.” 
Sir J. Herschel concludes his paper on Mr. Abbott’s statements 
by expressing the hope that some southern observer furnished with 
an equatorially mounted telescope would without further delay set 
to work in earnest, and map down the stars visible in this most 
interesting area, down at least to the 10th or 11th magnitude. 
The questions raised by Mr. Abbott’s paper “are of the last 
importance,” says Herschel, “and must be settled.” 
Father Secchi, in a letter addressed to Admiral Manners, describes 
the spectra of fifty red stars. He examined these with a spectroscope, — 
the construction of which had been improved (in the Padre’s 
opinion) by the use of cylindrical lenses (only) for the eye-piece, 
which was made by M. Merz, and worked admirably. He points 
out that a new type of stars appears in the list, wz. that of stars 
having a spectrum of three large coloured zones. He has already 
found several of that type. He is particularly surprised “to see 
some zones always at the same places, so that there is a great 
cosmical law which is about to come forth; but for the present,” 
he adds, “ we must wait until the review of all the stars has been 
accomplished.” It is to be wished that the good Padre would 
VOL. V. 2Q 
