F.57 Data Sheet MJS-p-0271

E.S.A. London, Harrow Mark Reducer, 1898-1925

Serial Number or Date Stamp:

Country: UK Primary construction material: wd Case included?: no

General Description: Early linear marking/grading rule slide rule

Length of 1 decade = 11 in, and overall scale length = 33 in. The largest physical dimension is 36 in.

Front Scales: A [ B ]

Back Scales:

Notes: Educational Supply Association, incorp. 1898; rule was designed in 1875 by W.D. Bushell for the Harrow School, England, to reduce and calculate examination scores; 2 decades on stock, 3 decades on slide, 36 inch total length

References: A History of Harrow School, 1324-1991, Oxford University Press, 2000, p.312

Date Acquired: 08/03/2022