DE Fragment in Havard University

CHSI - The Collection of Historical Scientific Instruments, Harvard University

Fragment of Babbage's first difference engine
Inventory Number:  1991-1-0001a

Numerical ring from Babbage's first difference engine
Inventory Number:  1991-1-0001b

During the 1930s it was reported by Howard Aiken that Havard possessed one of the fragment's of Babbage's Difference Engine made by H.P. Babbage. This is still to be found in the lobby of the laboratory. See "Babbage and Aiken with notes on Henry Babbage's gift to Harvard of a portion of his father's Difference Engine" by I. Bernard Cohen in Annals of the History of Computing December 1988. This model has one figure wheel adding to two.

Havard University Library:
University Archives I.5.150; Eliot C.W., Box 75,1886: Letter H.P.Babbage to the Principal of the University 25th Nov 1886 offering the model as a gift to the university.
University Archives V 298.2005. File: Babbage R.H. Instructions how to operate fragment by H.P. Babbage and History of Fragment.

References

http://www.virtualtravelog.net/2004/03/charles-babbage-and-howard-aiken-how-the-analytical-engine-influenced-the-ibm-automatic-sequence-controlled-calculator-aka-the-harvard-mk-i/