A defunct Downtown tool business lives on—thanks to this faded ad on the side of its former headquarters

Ann Street is one of New York’s oldest streets. On a recent Saturday, this three-block stretch of the Financial District resembled a slender ghost town of turn of the century commercial buildings. But look up on the western wall of 42 Ann Street. You’ll see a historic painted ad that harkens back to the days of slide rules and mechanical drafting tools. “Drawing Materials, Surveying Instruments, Measuring Tapes” the last three lines of this faded ad read. The top line announces the name of the business, “Keuffel & Esser Co.” Few people outside of collectors of vintage engineering equipment would recognize Keuffel & Esser. Founded in 1867 by German immigrants Wilhelm J. D. Keuffel and Hermann Esser, the company manufactured and imported tools that were used in some of the era’s major engineering feats. Keuffel & Esser, “provided the tools that explorers and builders relied on for expeditions to the North Pole and across the American continents and for such engineering marvels as the…