The back is stamped: "Johnston Brothers, Inc.;lPackaged Boiler Manufacturers; Ferrysburg, Michigan; Pioneers of Submerged Rear Combustion Chamber Boilers." Also has the Johnston Brothers Logo in green. The object consists of the slide rule and case.
Manufacturer
Johnston Brothers, Inc.
Place Manufactured
U.S.
Identifying Numbers
Other number
P144
Donor's ID number for rule
Dimensions
overall: 1/4 in x 6 1/4 in x 2 in; overall: 1/4 in x 6 in x 1 1/4 in
