Robert McKim, donor of the observatory at De Pauw University 

 (q.v. ), built an observatory near his home in Madison, Indiana, in 1883. 

 This observatory, reputedly the first in that state, was provided with two 

 refracting telescopes made by Alvan Clark & Sons. One, of 4 inches aper- 

 ture, had a portable equatorial mount. The other, of 6 inches aperture, 

 had a fixed equatorial mount and various accessories made by Fauth. 168a 



Joel Hastings Metcalf (1 866-1 925), an astronomer connected 

 with Harvard College Observatory, had a private observatory at Taun- 

 ton, Massachusetts. Among his instruments was a Clark equatorial of 

 7 inches aperture. 169 



Miami University, at Oxford, Ohio, bought the 12-inch Clark re- 

 fractor from Wesleyan University (q.v.) about 1920. They have since 

 given it to the amateur astronomer, Leslie Peltier (q.v.). 



The apparatus used by Albert A. Michelson in 1879 for his first 

 measurement of the speed of light incorporated five basic optical pieces. 

 Sunlight, introduced by a heliostat, was reflected by a small revolving 

 mirror to a lens of long focal length ; a fixed mirror located at the focus 

 of the lens reflected the light back through the lens to the revolving mir- 

 ror, and the deflection of the light was measured by a micrometer. The 

 heliostat was designed by Keith, and the micrometer was made by 

 Grunow. The mechanical part of the revolving mirror was made by 

 Fauth ; the mirror itself, a disc of glass 1 l /$ inches across, silvered on the 

 front surface, was made by the Clarks, as were the lens and the fixed 

 mirror. Because of its unusually large focal ratio — reminiscent of 17th- 

 century aerial telescopes, this lens was of 8 inches aperture and 150 

 feet focus — the lens was not achromatized. The fixed mirror, 7 inches 

 wide, was actually one of the heliostat mirrors used in photographing the 

 1 874 Transit of Venus ( q.v. ) . 17 ° 



In 1880, for the use of their students, the University of Michigan 

 purchased two instruments with Clark optics and Fauth mounts. 171 The 



16?a Edward S. Holden, ed., "Astronomy," Smithsonian Institution . . . Annual 

 Report . . . 1883, p. 428. 



169 P. Stroobant, Les observatoires astronomiques et les astronomes (Brussels, 1907), p. 234. 



170 Albert A. Michelson, "Experimental Determination of the Velocity of Light," 

 Proc, American Association for the Advancement of Science, vol. 28 (1879), pp. 130-135. 



171 Publications, Astronomical Observatory of the University of Michigan, vol. 1 (1912), 

 history and apparatus. Also, private correspondence with Orren C. Mohler, Chair- 

 man, Department of Astronomy, University of Michigan. 



80 



