B58-551 PROTRACTOR LEVEL. Loeschner Patent. Patented in 1921 by Henry Loeschner of Fredericktown, MO, and features a central compartment that can be popped out of the stock and used separately as a gravity inclinometer. In addition to the hanging indicator, some (but not all) of these levels have four level vials glued inside the central compartment, but not part of this example. 24" long with a scaled ruler on the top rail. The wood has been lacquered. Good+ 500-1000