58 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



The Sidereal Clock, which was made by Gregg & Rurr, has a 

 mercurial pendulum. 



The Solar Clock was made by W. II. C. Riggs, of Philadelphia. 



The Telescope, Transit Instrument, the Alt-azimuth Instrument, the 

 Transit Theodolite, and the Sidereal Clock stand on slabs of limestone 

 which rest on brick piers that descend about four feet into the 

 ground, and have no connection with the floors. The Solar Clock 

 hangs on the pier which supports the Telescope. 



In May last a telegraph line was run connecting the observatory 

 with the lines of the Western Union Telegraph Company. 



Work Done. During 1877-78 the seniors have had a large amount 

 of practice, both in the adjustment and use of the instruments. The 

 different methods, of determining latitude and longitude have re- 

 ceived special attention. In this work I have had the assistance of 

 Professor Thomas J. Lowry, of the Department of Civil Engineer- 

 ing, who has an experience of seven years in the work of the U. S. 

 Coast Survey. 



The transit of Mercury which occurred on the 6th of May last 

 was successfully observed by Professor Lowry and myself. I made 

 observations, also, on the eclijjse of the sun, July 29. Reports of 

 these observations have been sent to the Superintendent of the U. S. 

 Naval Observatory at Washington. 



From the 3d to the lOtk of May, inclusive, time-signals, made by 

 connecting the pendulum of the clock in the Naval Observatory 

 with the lines of the Western Union Telegraph Company, were re- 

 ceived and compared here with our local time. This part of the 

 work was of special value, as it enabled us to determine our longi- 

 tude with great precision. 



Columbus, 0. : Ohio State University. 



T. C. Mendeniiall, B.Sc, Physics ; R. W. McFarland, A.M., 



Mathematics. 



This university has no regular observatory; but such appliances 

 as we have are used on all proper occasions. The college owns one 

 small Portable Transit too small for valuable observations. But I 

 have the use of one Telescope 2.2 inches clear aperture, made by 

 Si.mms, of London; also of one Alt-azimuth Instrument belonging to 

 Miami University, Oxford, O., 3 inches aperture, 28 inches focal 

 length excellent of its kind. 



In connection with Professor T. C. Mendeniiall, I made regular 

 observations on the transit of Mercury in May, 1878 at least, of as 

 much of it as was visible an account of which was duly transmit- 

 ted to the Washington Observatory. 



The latitude and longitude of the Ohio State University building 

 centre of front entrance has been very carefully taken several 



