TRANSACTIONS OF THE SECTIONS. 13 
degree of efficiency has not yet been arrived at, or the highest degree of convenience 
attained for all the various occasions required in practice. 
The naval officers, who know what these difficult circumstances are, unfortunately 
are not in a position to remedy the defects of their instruments; while the makers 
thereof, living at home at ease, cannot fully appreciate all the difficulties actually 
met with in real practice at sea. This has left room for a person like the author, 
who has had some practice at sea and some experience in instrument-making, to 
effect several minor improvements of a practical character. 
The ordinary form of the reflecting instrument at present in use is the sextant, 
in which will generally be found, even as made by the best makers, more or less of 
the following little practical drawbacks upon the speedy and accurate employment 
of it. 
It is packed in its box in a way difficult to be got out, the handle, by which it 
ought only to be touched, being below: also it cannot be laid down anywhere 
without a changing of the hands and the incurring of risk in handling parts which 
should be sacred from the touch. 
Next there are several loose parts, as the telescope, plain tube, dark glasses, &c., 
which have to be screwed on before an observation can be taken, and time is lost 
thereby; even then too it may be often found with faint stars at night, that the 
object-glass of the telescope is prejudicially small, and the reflectors insufficiently 
bright, as well as erroneous at extreme angles, on account of the impossibility of 
procuring perfect glass, besides giving the nuisance of images from each surface, &c, 
Then, supposing the observation taken, there is such a needless difficulty in read- 
ing off the divisions, a difficulty not felt by beginners alone, but equally by practised 
naval officers, who give that as a reason why the very important class of observa- 
tions of stars by night is so little practised at sea. 
Finally, the observation when read off at last is taken merely upon a sextant or 
part of a circle, and is therefore liable to errors of excentricity and motion of the 
centre, and this to an unknown extent, and not constantly, as they may be influenced 
by accidental causes unknown to the observer. It is essential to the accuracy and 
the honesty as it were of observations, that they should be taken with some form of 
circle with opposite readings; many such have been brought forward in England 
and France, but owing apparently to their greater complexity, size and weight, they 
have not obtained a footing amongst practical-men. 
The author then exhibited a reflecting instrument which he had had constructed 
by Messrs. Adie of Edinburgh, and which appeared to supply all the desiderata, for 
it was in the shape of a circle, small, light, and simple, with the delicate parts pro- 
tected from injury under all circumstances: the usual loose telescope and plain tubes 
were avoided by making them cross through each other and work on a pivot, thus 
admitting of instant alteration from one to the other; the illuminating apparatus 
was improved and rendered powerfully effective even with a faint light ; and a small 
apparatus was added, which, without sensibly cumbering the instrument, gave, either 
by night or by day, a convenient horizontal referring point, visible in the field of 
view. 
Some Remarks on the Red Prominences seen during the Total Solar Eclipse. 
By Professor C. Prazzt Smytu, F.R.A.S. 
When the Members of the Association separated last year at Ipswich, it was under 
circumstances of peculiar astronomical import, viz. the impending occurrence of the 
total solar eclipse in a neighbouring region: many astronomers started to observe 
the phenomenon to the utmost, and more especially everything having relation to, 
or tending to throw any light on the physical characteristics of the sun; amongst 
which the “red prominences” were considered the most promising and important. 
The author was amongst the number of observers who started with these objects 
in view, but was totally defeated by the occurrence of clouds. Having been pre- 
vented then himself from seeing the red prominences, he thought it proper to defer 
to the opinions of those observers who had been more fortunate, and who seem in 
