54 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



in the world till a few years ago ; and now has only one superior in 

 the United States. It has recently been refitted and much improved, 

 and the upper portion of the tower has been reconstructed by the 

 Chicago Astronomical Society. The Telescope is fitted with Driv- 

 ing-clock, Micrometer, Spectroscope, and other appliances necessary for 

 first-class work. The dimensions of the Equatorial are : diameter of 

 declination circle, 30 inches ; reading by vernier to 5 minutes, and 

 by two microscopes to 10 seconds, of arc. Diameter of hour circle, 

 22 inches ; reading by vernier to single minutes, and by microscopes 

 to single seconds, of time. Focal length of object-glass, 23 feet. Ap- 

 erture of object-glass, 18f inches. 



11 (2.) A Meridian Circle, of the first class, constructed in 1867, by 

 Messrs. A. Repsold & Soxs, of Hamburg. This instrument has a 

 telescope of six French inches aperture, and a divided circle of forty 

 inches diameter, reading by four microscopes. In plan of construc- 

 tion it is like Bessel's celebrated Konigsberg circle, by the same 

 makers. Within the past two years a Chronograph has been adebd 

 for making an electrical record of the times of star-transits. 



" The observatory has a Chronometer (William Bond & Son, No. 

 279), two Mercurial Pendulum Clocks, and an astronomical library 

 containing nearly one thousand three hundred volumes and pam- 

 phlets. 



"Instruction in astronomy to the undergraduates is at present 

 given by the Superintendent. 



" The observatory is now supplying time-signals each day in the 

 year, by telegraph, to several different points in the city of Chicago, 

 and its time is the standard for many other points in the West." 



3d. WorJc of 1878. I have not much to report. The fire of 1871 

 and the panic of 1873 demoralized finances. I took hold in 1874, 

 raised money by subscription to put on a new dome, etc., and have 

 since taught in the university. I am not paid for any of this, and 

 have little time left after this and a regular round of duty as one of 

 the editors of the Tribune. Till last April I resided five miles away. 

 I then removed to neighborhood of observatory, and have since done 

 a little work. 



Observed transit of Mercury, May G. 



Observed solar eclipse of July 29 at Denver, Col. Chief points: 

 made a class-drawing of corona ; and Professor Lewis Swift, of our 

 party, found Vulcan. I published a pamphlet report on the eclipse 

 which was widely distributed. 



I am now using the Transit Instrument, and, 



4th. WorJc of the Future. I expect to continue work with it in 

 1879, observing stars in aid of Professor Saftbrd, formerly Director 

 here, and now at Williams College, Mass. 



Mr. Barton keeps the time. He is the only salaried man in the 



