Solar Compass

W. & L. E. Gurley began advertising solar compasses in 1858, acknowledging that these instruments had "come into general use in the surveys of U.S. public lands, the principal lines of which are required to be run with reference to the true meridian." Gurley went on to state: "The invention, having long since become the property of the public, we have given our attention to the manufacture of these instruments, and are now prepared to furnish them, with important improvements of our own devising, at greatly reduced prices."

The earliest Gurley solar compasses that have yet come to light are dated 1859, and they differ in a few small ways from the 1858 illustration. Most notably, the tangent screws were moved closer to the arcs. This example, which the University of Georgia purchased shortly before the outbreak of the Civil War, is of that type. The horizontal circle is silvered, graduated to 30 minutes, and read by opposite verniers to single minutes. The finish is anodized. The inscription reads: "W. & L.E. Gurley, Troy, N.Y." The words "G. A. Raymond Jan. 1860" are scratched on the underside of the plate. George A. Raymond joined Gurley in 1853. He was given responsibility for assembling and adjusting solar compasses in 1858, and was still with the firm in 1889.

Ref: W. & L. E. Gurley, Manual of the Principal Instruments used in American Engineering and Surveying (Troy, N. Y., 1858), pp. 64-93.

William H. Skerritt, "The Solar Surveying Instruments of the W. & L. E. Gurley Company," Rittenhouse 3 (1988): 15-22.

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