/. — Introduction. 



The Detroit Observatory of the University of Michigan was built about 

 1854 throu,c;h the efforts of President Tappan, money for the purpose 

 being raised in Detroit. Mr. Henry N. Wallver of Detroit was es7»ecially 

 interested in tlie project and gave funds for the purchase of the meridian 

 circle. 



The observatory building is of the usual old-fashioned type, a central 

 part, on the top of which is the dome for the equatorial, and east and west 

 wings, the meridian circle being in the east wing and the library in the 

 west. All the walls are of heavy masonry, so that the temperature in the 

 observing rooms changes slowly. 



In addition to the Walker meridian circle the observatory was equipped 

 at first with a 12%-inch equatorial constructed by Fitz, and a clock by 

 Tiede of Cerlin. The equatorial has the old German style of mounting 

 with a wooden tube. As far as I can find out the driving clock was never 

 of any use. Also, it is rather difficult to manage the illumination of the 

 micrometer, so that with it few systematic observations were made. The 

 object glass is a fair one. With this instrument Professor Watson dis- 

 covered twenty-one asteroids. A number of these were observed but a 

 few times and are now lost. The difficulty in using the micrometer is 

 probably the reason for the small number of observations of them made 

 at Ann Arbor. 



Observations of comets and asteroids were also made with this instru- 

 ment by Dr. Briinnow, Professor Watson and Messrs. Schaeberle, Camp- 

 bell, Hussey, and Townley. I believe that several comets were discovered 

 with it. 



The Tiede Clock has now an irregular rate. 



About 1880 a small observatory was erected near the large building, 

 designed especially for practice work. In it were placed a 6-inch equa- 

 torial with a Clark glass, and mounting by Fauth, and a 3-inch Fauth 

 meridian transit. 



The object glass of the equatorial is good, wilh the sharp definition 

 characteristic of the Clark glasses. The mounting is fair, though the 

 driving clock, having a Foucault governor, is too weak. 



With this equatorial observations of comets and asteroids have been 

 made by Messrs. Schaeberle, Campbell, Hussey, and Townley. 



The object glass of the meridian transit is poor. AUrsae Minoris cannot 

 be seen with a bright field. The pivots rest on wide and flat agate bear- 

 ings, an arrangement which is wrong mechanically, and may account for 

 the existence of two azimuths. 



The observations made at Ann Arbor have been i)ublished in the various 

 astronomical journals and in the American Journal of Science. In the 

 way of records there is very little. 



The observatory building is on a hill south of the Huron River, on clay 



