OP NEBULiE AjSTD CLUSTERS OP STARS. 
7 
zone in order of II. A., and reduced to the year 1800 by Miss C. L. Herschel, exhibiting 
the reduced result of each separate observation of each nebula ; together with the deter- 
mining star or stars in each case, and the differences of R.A. and P.D. from such star, with 
references to the current number of the sweep in which the observation is contained. 
7th. The original sweeps with the 20-feet reflector at Slough in which the nebulae 
were observed, contained in three small quarto and four folio volumes of MS. 
All these manuscripts, with exception of the index No. 3, are in the original hand- 
writings of my Father and his Sister, in most cases easily distinguishable, in some others 
not so readily. The Zone Catalogue No. 6 is entirely the autograph of the latter. 
Explanation and arrangement of the Catalogue. 
The Catalogue is arranged in twelve columns, of which the first contains the general 
or current number in order from 1 up to 5063, the total number of objects comprised, 
including six supplementary ones, whose insertion in their proper order in R.A. would 
have involved altering all the numbering both of the catalogue and the annotations, &c., 
and would have proved a source of confusion and unavoidable error. Nevertheless, to 
prevent their being overlooked by any observer who may consult the catalogue for the 
purpose of a general review of the nebulae, or for the verification of a new one, their 
numbers are interpolated into the general series so as to catch the eye, and a reference 
made to the supplementary catalogue in each case in the column of descriptions. 
Column 2 contains the numbers of those nebulae of which observations are given in 
my two former catalogues, and those of the two nubeculae ; the numbers from 1 to 2307 
inclusive being from that in Philosophical Transactions 1833, and from 2308 to 4021 from 
my Cape observations. Where a number in this column is enclosed in hooks thus [ ], it 
is taken from the Catalogue of Objects in the Nubecula minor in pp. 153 to 155 of that 
work. Where in parentheses thus ( ), from those in the Nubecula major, pp. 156 to 163. 
Column 3 contains the classes and numbers of nebulae as given by my Father in his 
three Catalogues in the Philosophical Transactions for 1786, 1789, and 1802. One only 
is omitted, viz. V. 35. It is an immense diffused nebulosity, extending from 5 h 27 m to 
5 h 42 m in R.A., and from 98° 6' to 87° 43' in P.D. A special list of these great diffusions 
of nebula is given by M. Auwers in p. 42 of the work above cited. 
Column 4 contains references to other authorities, and gives either the name of the 
first discoverer of the nebula, or a reference to the particular list or catalogue of nebulae 
which has been taken as the authority for the place set down. The principal of these are 
— 1st. The list of “new nebulae” (Verzeichniss neuer Nebelflecke), in pp. 73 to 76 of the 
work of M. Auwers already cited. These are referred to in the following form : — Auw. 
N. 1, Auw. N. 2, &c. 2ndly. Under the form D’Arr. 1, 2, &c., are given a series of objects 
contained in a MS. list of 125 nebulae, kindly communicated to me by their discoverer, 
M. D’Arrest, Director of the Royal Observatory of Copenhagen, and reduced by him to 
the epoch (186(H)) of this Catalogue, with their precessions for 1880. 3rdly. A great 
number of nebulae cited under the form “ R. novae,” whose places have been approxi- 
