64 AMEEICAN ASSOCIATION TOE THE ADVANCEMENT OE SCIENCE. 



what miscellaneous assemblies may perhaps fully justify. But -whatever may he 

 the effects of this absence of the predominating element of youthful aspirants for 

 honors in the field of Scientific adventure, the assembly of so many of the most 

 distinguished representatives of American Scientific Veterans, was a peculiarly 

 acceptable feature to those who were allured from other countries, by the echo 

 of their fame. Nor must it be overlooked that in whatever other respects the 

 popular element may work, it is scarcely possible for a warmer or more hospita- 

 ble welcome to be offered any where, than that which the citizens of Albany, and 

 the Official representatives of the State of New York, tendered to the assembled 

 Congress of American Science, and to the visitors attracted by the justly earned 

 reputation of its members. 



The great feature of interest at this meeting was the inauguration of the 

 Dudley Astronomical Observatory. This observatory has been founded by the 

 liberality of some citizens of Albany, among whom Mrs. Dudley, whose name it 

 bears, has not only contributed upwards of $25,000 for the building and instruments 

 but has anuounced a further donation of $50,000 towards its permanent endow- 

 ment. The Hon. Edward Everett delivered a splendid oration on the occasion, 

 in the presence of the Association, the dignitaries of the State, and the citizens of 

 Albany, the venerable foundress herself occupying the seat of honour. The ob- 

 servatory is built in a solid and massive style, and finely situated on the brow of 

 a hill ; its erection was superintended by a committee of eminent astronomers, and 

 the construction of the instruments was entrusted to Dr. Gould, who has accepted the 

 appointment of Director. At a meeting in Section, Dr. Gould described in detail 

 the new instruments. The minor instruments have been received, and the Obser- 

 vatory has been fitted up with these and others lent by Prof. Bache from the 

 Coast Survey, but the reception of the larger instruments will be delayed for a 

 few weeks longer. The Transit circle, combining in one the Transit telescope and 

 meridian circle, was ordered from Pistor and Martius, the celebrated manufac- 

 turers of Berlin, by whom the new instrument at Ann Arbor was made. A 

 number of improvements have been introduced in the Albany instruments, not 

 perhaps all absolutely new, but an eclectic combination of late adaptations with 

 new improvements. Dr. Gould made a distinction of modern astronomical in- 

 struments into two classes, the English and the German. The English is the 

 massive type ; the German, light and airy. The English instrument is the instru- 

 ment of the engineer ; the German, the instrument of the artist. In ordering the 

 instruments for the Albany Observatory, the Doctor had endeavoured to combine 

 the two, with, however, a preference to the German type. The circle is three 

 feet in diameter, graduated to intervals of two minutes, and read by micrometers 

 to tenths of seconds. The microscopes are four in number, and are not carried by 

 moveable frames, but are imbedded in the piers. The piers theraselves completely 

 surround the circle so as to eliminate the effect of changes of temperature by radi- 

 ation. The tube of the telescope is eight feet in length, and the object glass is 

 eight inches clear apei'ture. The glass was made by Chance, of Birmingham, and 

 ground by Pistor himself. The eye-piece, in addition to the diaphragm, is fur- 

 nished with two micrometers, one for vertical, the other for horizontal motion, the 

 use of these being for the cireumpolar stars, whose motion is too slow for registration 

 by the Chronographic method. One principle has been adhered to in the whole of 

 the instrumental arrangements, namely : that every error is capable of being de- 

 termined in two independent ways. 



