This instrument, which belonged to Columbia University, was made after 1874 when
Fauth & Co. began in business, and before 1887 when Saegmuller began putting serial numbers
on Fauth instruments. Fauth termed it a "Combined Transit and Zenith Instrument, as devised by
Prof. G. Davidson, U. S. C. S." The frame consists of two parts--the upper one, with the
uprights, can revolve upon the lower. New, it cost $990. This example differs from the
instrument shown in the Fauth Catalogue in that here the small vertical circles are placed at one
end of the horizontal axis.
Ref: Fauth & Co., Catalogue of Astronomical and Surveying Instruments (Washington, D.C.,
1877), pp. 20-21.
George Davidson, "Description of the Davidson Meridian Instrument," United States
Cost and Geodetic Survey Annual Report (1879), Appendix No. 7.