REPORTS OF AMERICAN OBSERVATORIES. 561 



s 

 which is circular, and 1G feet in diameter inside. It is also a little more 

 than 16 feet from the floor to the highest point of the dome. The dome 

 is a hemisphere, and rests on twelve sheaved rollers, and is revolved by 

 machinery at the pleasure of the observer. 



The transit is already received. It was made by Messrs. Fauth & Co., 

 of Washington, at a catalogue price of $900. Its telescope has 3 inches 

 dear aperture and 3i feet focal length. It has a striding level reading 

 to seconds of are, a G-inch setting circle with level alidade on axis di- 

 vided on silver and reading to thirty seconds, glass micrometer instead 

 of spider lines, illumination on the new plan through the axis with side 

 reflector, so as not to interfere with the object rays. The clamp is of 

 the improved Davidson form. One of the Y's can be moved in azimuth 

 and the other in altitude. The transit is also provided with a neat and 

 convenient reviewing apparatus that will add much to facility in work. 

 Before the instrument was shipped from Washington it was tested by 

 Professor Hilgard, one of the leading officers of the Coast Survey, who 

 acted as chairman of the committee of judges on astronomical instru- 

 ments at tie late Centennial Exposition. He pronounces the transit 

 excellent in design and finish. 



The observatory will be provided with two clocks, a sidereal and a mean 

 time, costing about $500 each. The former is already in place and nearly 

 regulated. The latter is expected daily. 



A 4-inch equatorial portable instrument has been ordered, at a cost of 

 about $400. Correspondence is now being had respecting the purchase 

 and making of a large 8J-inch equatorial instrument. It is to be mounted 

 in the best style, and to be provided with a driving clock. It cannot be 

 completed in less than six months, and therefore may not be received 

 until late this fall. It is, however, hoped that it may be secured and set 

 ready for use this coming winter. Its cost will not vary much from 

 $3,000. 



CARLETON COLLEGE TLME SIGNALS. 



Few of those who have visited the observatory of Carleton College, 

 in our city, have definite knowledge of the system of daily time signals 

 which are given from it. Very little has been written or published re- 

 specting the details of regulating the time by astronomical observa- 

 tions, or of the noon-day distribution of it over the vast area of portions 

 of six different contiguous States. 



It is not our purpose now to describe either branch of this practical 

 or useful work to which the instruments of the observatory have been 

 mainly devoted for the five months since it was erected, but rather to 

 mention a few facts respecting the time signals that have been noticed 

 by friends of the institution who have asked for a brief statement of 

 them for publication. 



The observatory is connected with the main line of the Northwestern 

 Telegraph Company, and hence may use. at pleasure, either the commer- 

 cial or the railroad line for communication with any distant points. By 

 S. Mis. 54 3G 



