1 14 Mr. iierschel’s Catalogue 
added Inaccurate , we may fufpedl an error of 3 or tj f . Exaffily 
ejlimated may be taken to be true to about one-eighth part of 
the whole diftance ; but only ejlimated. , or about , &c. is in 
fome refpeft quite undetermined ; for it is hardly to be con- 
ceived how little we are able to judge of distances when, by 
conftantly changing the powers of the inftrument, we are as it 
were left without any guide at all. I fhould not forget to add, 
that the inealure of liars, whereof one is extremely fmall, 
muff claim a greater indulgence than the reft on -account of 
the difficulty of feeing the wires when the field of view cannot 
be fufficiently enlightened. 
V. The angle of polition of the ftars I have only given with 
regard to the parallel of declination, to be reduced to that with 
the ecliptic as occafion may require. The meafures always fup- 
pofe the large ftar to be the ftandard, and the fituation of the 
fmall one is defcribed accordingly. Thus in figure 12. AB re- 
prefents the apparent diurnal motion of a ftar in the direction 
of the parellel of declination AB ; and the fmall ftar is faid to be 
fouth preceding at mn 9 north preceding at op , fouth following 
at qr 9 and north following at st. The meafure of thefe 
angles, I believe, may be relied upon to 2 0 or at moft 3 0 , ex- 
cept when mentioned inaccurate, where an error amounting to 
5 0 may poftibly take place. In mere eftimations of the angle, 
without any wires at all, an error may amount to at leaft io°, 
when the ftars are near each other. 
VI. The dates when I firft perceived the ftars to be double, 
treble, &c. are marked in the margin of each ftar. 
To fhorten the work as. much as poflible, 1 have put L. for 
the large ftar ; S. for the fmall ftar ; w. for white ; r. for red ; 
d. for dufky ; n. for north; f. for fouth ; and have likewife 
occa- 
