Friday, September 29, 2023

Autumn 2023 report to the Computer Conservation Society

Project Report to Computer Conservation Society Committee for 21 September 2023

The omission of regular reports is not indicative of a drop in activity. Quite the opposite. My last report signalled a turning point: Tim Robinson’s panoramic and detailed technical description of Babbage’s designs for the Analytical Engine put us in a position, for the first time, to specify what would be meaningful to build.

In March last year I reported that we needed to expand the team to include expertise that we did not have – primarily solid modelling and mechanical engineering, and the report was an invitation, a call, a plea, for expressions of interest to take the project forward. We have had a promising response. Len Shustek, Chairman Emeritus of the Board of Trustees of the Computer History Museum, picked up the gauntlet and set about engaging with Tim’s technical description of the AE and assessing options for going forward. This exploratory collaboration has been a welcome relief to Tim who has been working for the last six years in near-complete isolation. Discussions are ongoing about the algorithms Babbage proposed for computational process, the prospective role of various forms of simulation, and criteria of authenticity in our design of apparatus where Babbage’s provisions are less than complete. Discussions are ongoing about how to finesse the balance between fidelity to the original designs and their practical feasibility. Moving to implementation invokes issues of funding, project management, intellectual ownership, and hosting the eventual build.

Since the last report Tim has expanded the knowledge-base with an extended account of Babbage’s Mechanical Notation – Babbage’s quasi-mathematical language of signs and symbols that he used to describe mechanisms and their operation. Tim’s description includes the historical development of the Notation and Babbage’s use of it in his engine designs, especially for the Analytical Engine about which practically nothing has been published. The account runs to 16,000 words which extends the length of the overall account to some 140,000 words, a treatise that ranks as a defining treatment to date of Babbage’s work on calculating machines.

So the knowledge base is sound and provides an unprecedentedly well-founded platform for implementation.

Just over 200 years ago Babbage wrote:

Whether I shall construct a larger engine of this kind, and bring to perfection the others I have described, will in great measure depend on the nature of the encouragement I may receive.

- (Charles Babbage to Sir Humphrey Davy, 3 July 1822).

Doron Swade


  1. Exciting times! Is there a chance of Tim's master-work being published or made accessible to the public?

  2. Just a note to congratulate you all on your hard work which is now bearing fruit.

  3. Always exciting to receive an update on this project! The 140,000 word knowledgebase sounds like a very valuable resource that I hope will, aside from facilitating the reconstruction project itself, also facilitate new publications on Babbage's work.