ASTRONOMICAL OBSERVATORIES. 399 



South IIadley, Massachusetts. 



Ohscrvafory of Mount Holyoke Seminary. 



Longitude from Washiiii^tou, 17"' 51.75^ E. 

 Latitude, 42° 15' 18.2" N. 



Authority for longitude: R. IJ. West, by telegrapliic communication 

 with Cambridge at the time of the transit of Venus. For lati- 

 tude: C. A. Young, by zenith telescope method. 

 Director: Miss E. ]\I. P.ardwell. 



Through the liberality of Mr. A. L. Williston, of ^Northampton, the 

 seminary has recently been enabled to erect a small but very complete 

 astronomical observatory, supplied with all the necessary instruments. 

 It is designed to furnish the means for instruction to any who may wish 

 to make the subject a specialty, and to give opportunity to any of the 

 teacherff or post-graduates who may take an interest in astronomy to 

 make observations of real value. 



The building, of wood, consists of a tower with a dome 18 feet in 

 diameter, tianked by two wings, one extending to the east and one to 

 the north. The dome is very light, and rotates so easily that even the 

 feeblest of the young ladies can manage it without difliculty. The ar- 

 rangements for opening and closing the shutters which cover the slit in 

 the dome, and the openings for the transit and prime vertical instru- 

 ment, are worked with equal facility. In the dome is mounted a fine 

 8inch ecpiatorial by Clark, completely fitted out with clock-work, 

 fin ding- clock, micrometers, spectroscope, solar eye-piece, etc., and so 

 arranged that the circles can be read and the clamps and tangent 

 screws worked from the eye-piece of the instrument. 



The object-glass is almost entirely the work of the senior Alvan 

 Clark, and is one of the most perfect specimens of hisiirt. 



In the transit-room is mounted a meridian circle by Fauth & Co., of 

 Washington. The instrument has a telescope of 3 inches aperture, and 

 circles of IG inches diameter, reading to seconds by two microscopes. 

 It has a reversing apparatus, and is fitted with a " latitude level" and . 

 micrometer, so that it can, if desired, be used as a zenith telescope. A 

 large collimator is mounted upon a pier south of it, and in a corner of 

 the room is a clock with Denison escapement, also by Fauth & Co., 

 as is the clironograph, which is mounted in an adjoining closet. The 

 Observatory possesses also a sextant and artificial horizon and a set of 

 meteorological apparatus. 



There is no instrument in the prime vertical room (which is used 

 mainly as a waiting-room or for recitations), but it is provided with a 

 pier and shutter, so that the meridian circle can be set up there if it is 

 ever thought desirable to make observations in that plane. 



