150 Friedrich Georg Wilhelm Struve. 
and distance began to be at all consecutive at Dorpat, though 
differences of right ascension and declination had been pretty 
copiously observed. In 1820 appeared Struve’s first Catalogue 
of 727 double stars, arranged in the order of their right ascen-_ 
sion, together with their corresponding declinations. This Cata- 
logue was expressly intended to facilitate the observation of these 
Foes — with meridian or with equatorially-mounted in- 
truments, and Riese revived the subject as one of gene 
samen interest. 
Nevertheless, be cow ouch: and valuable as were these n 
attempts, it was not until the erection of the great Fraunhofer 
Refractor in 1824, at Dorpat, that Mr. Struve became posses 
of an instrument worthy of the subject, and competent, not only 
to afford facility and precision in respect of aia te but to 
add largely to the list of known double sta 
e result of the first two years of his plies nae with this 
famous telescope was that most remarkable work, Catalogus novus 
generalis Stellarum duplicium et muitiplicium, which appeared in 
1827, and will for ever be consi Son as forming a memorable 
epoch i in Sidereal Astronomy. Nor is this great work remarka- 
ble alone for its copious and valpasle lists of 3112 double or 
multiple stars duly arranged in their order of right ascension, 
situation as seen ? 
eneral rule of isolation, nor as mere curiosities of the si 
heavens, but as entering: Fe oy into the general plan and con- 
itution of the universe observations, carried on both 
r. Struve himself and by eS with even larger instru- 
Ean the great Dorpat refractor, have confirmed this most 
It, and have shown ae it is but an ordinary circum- 
: stars previous ly regarded as single, to be in reality 
close el uivala a will enhance our 
ur lamented associate, and enable 
labor and devotion required for the 
to emark that in the preface to 
y have been the result of 1! 
