VL Catalogue of Double Stars, 
By William Herfchel, Efq. F. R. S. 
Read December p, 17B4* 
INTRODUCTORY REMARKS, 
T HE great ufe of Double Stars having been already pointed- 
out in a former paper, on the Parallax of the Fixed Stars* 
and in a latter one, on the Motion of the Solar Syftem, I have 
now drawn up a fecond collection of 434 more, which I have 
found out fince the frit was delivered. 
The happy opportunity of giving all my time to the purfuit 
of aftronomy* which it has pleafed the Royal Patron of this 
Society to furnilh me with, has put it in my power to make 
the prefent collection much more perfeCt than the former $ 
almoft every double ftar in it having the diftance and pof tion 
of its two ftars meafured by proper micrometers ; and the 
obfervations have been much oftener repeated. 
The method of claffing them is in every refpeCt the fame as 
that which has been ufed in the firft collection ; for which rea- 
fon I refer to the introductory remarks that have been given 
with that collection * for an explanation of feveral particulars 
neceffary to be previoufly known. The numbers of the ftars 
are here alfo continued, fo that the frit clafs ending there at 
^ See Philofophical Tranfadions, Vol. LXXII. ps 112. 
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