Abstract: An electrically responsive level of the type used for determining inclination with respect to a gravity field is described. The instrument relies for its operation on a bubble-within-a-vial type of inclination sensor. The vial is generally rectangular in cross-section, and its dimensions and the size of the bubble therewithin are selected to assure that the instrument can be used reliably in the field without false readings and the like. The specific leveling instrument described is of the so-called carpenter's type and is usable not only to provide a visual and/or audio indication of a level condition, but also to measure or establish any inclination between the horizontal and vertical.