298 Miscellaneous Intelligence. 



feet wide, and extending a few degrees beyond the zenith; which is 

 closed by weather-proof shutters, and worked by means of an endless 



chain and toothed wheels. 



On the lower side of this dome is affixed a grooved iron rail, and on 

 the granite cap of the wall is placed a similar rail ; between these 

 grooves are placed eight iron spheres, accurately turned, on which the 

 dome is revolved. The apparatus for moving the dome consists of 

 toothed wheels, geared to a series of toothed iron plates, fastened to its 

 lower section. By means of this the whole dome, weighing about four- 

 teen tons, can be turned through a whole revolution, by a single person, 

 in thirty-five seconds. In this dome are placed the " Grand Refractor," 

 and one or two smaller instruments. The Comet Seeker, a small m- 

 slrument of four inches aperture, by Merz, is used from the balconies 

 of the dome. This is the instrument with which the younger Bond has 

 discovered no less than eleven telescopic comets, before intelligence 

 had reached him of their having been seen by any other observer. 

 From these balconies a most extensive and beautiful view of the neigh- 

 boring towns, meets the eye. ^ 



On either side of the tower is a large wing. Of these the eastern is 

 used as a dwelling for the observer; the western, on which is placed 

 the smaller dome, is used for magnetic and meteorological observations. 

 This wing was erected in the years 1850-51, and adds greatly to the 

 architectural beauty of the Observatory. In this dome is placed the 

 smaller equatorial, of five feet focal length, and an object-glass of four 

 and one-eighth inches, made by Merz, which is a remarkably fine in- 

 strument. 



The "Grand Refractor," justly considered second to none in the 

 world, has already become celebrated in the hands of the skillful and 

 scientific director and his assistant, from the many brilliant discoveries 

 which have been made with it. Among these we may particularly 

 mention the new ring and satellite of the planet Saturn. It has also 

 enabled the observers to resolve the principal nebulse, particularly those 

 in the constellations Orion and Andromeda. The object-glass was made 

 at the celebrated manufactory of Merz and Mahler, in Munich, Bava- 

 ria, who also were the makers of the celebrated telescope at the Pul- 

 kova Observatory, which is of the same size and mounting as that in 

 Cambridge. The same artists also made the Washington and Cincin- 

 nati equatorials, besides many others of a smaller size in the United 

 States. The extreme diameter of this object-glass is fifteen and a half 

 inches, although the effective diameter is only fourteen and ninety-five 

 hundredths inches: the focal length is twenty-two feet six inches; the 

 total weight nearly three tons ; yet the friction is so successfully reliev- 

 ed by the judicious arrangement of wheels and counterpoises, that it 

 could be pointed to any quarter of the heavens by the finger of a child. 

 A siderial motion is communicated to the telescope by clock-work, 

 by which means an object may be constantly kept in the field of view, 

 which essentially aids the observer in delicate examinations of celes- 

 tial objects. The right-ascension is read off by means of an hour cir- 

 cle, eighteen inches in diameter, reading to one second of time by a 

 vernier, while the declination circle is tweniy-six inches in diameter, 



reading also to one second of time or four seconds of arc* The total 



