This highly significant engineering instrument is a Bausch & Lomb Saegmuller "Precise Level," manufactured in Rochester, N.Y., and built to U.S. Coast and Geodetic Survey specifications circa 1907. A true collector's piece, the 17-inch telescope is constructed with an Invar (nickel-iron) outer tube and an Invar (nickel-steel) inner tube for maximum thermal stability during field measurements. The green-painted finish shows rare, authentic traces of chopped cloth insulation, a specialized feature of this model's historical configuration. Bearing serial number 6721, this piece represents the brief period from 1905 to 1907 when the Bausch, Lomb, Saegmuller Company was formally in existence. The lot includes the original fitted mahogany carrying case with a fully functional lock and original key, two eyepieces, and a protective canvas bag. The instrument is in excellent condition, having been professionally cleaned and maintained, with the mahogany case showing only minor age-appropriate scuffs and surface wear to the finish. H 9", W 20.25", D 10.25".". From the collection of Dale Beeks. Please see photos for condition.