|Other number||#518||Verso pencil|
Dimensionsoverall: 4 in x 5 in
DescriptionBlack and white image of a MADAS Calculator. A long rectangular box with across the top a series of round windows with numbers showing.
To the right are 8 rectangular holes each with 10 noptches and a push slide, There are slides for addition, multiplication, subtraction and division.
Printed on box: MADAS Pat Jahnz U.S.A. P# DEC. 16th, 1913 D.R.P. etc.