Iliff's Land Survey Store Offered the Invertometer

Iliff's Land Survey Storeat offered the Invertometer, a tool used to measure the elevations of pipe inverts by subtracting a calculated distance "A" from the man hole rim elevation. Eliminating the need for string lines and making measuring the depth of hard-to-reach pipe inverts quick and easy, the Invertometer does not need to be bolted onto a level rod or range pole. Welded aluminum construction with uhmw inserts holds the removable rods snug. (Iliff's, Aurora, Ill.)