Tuesday, May 3, 2016

Winter 2015: Project Report to the Computer Conservation Society

The following report appeared in the Winter 2015 Resurrection:

The bicentennial year of Ada Lovelace’s birth falls this year. Preparation for various celebratory events has directed attention to Ada Lovelace’s ‘program’ (1843) to calculate Bernoulli numbers using Charles Babbage’s unbuilt Analytical Engine. A small group including Tim Robinson in the US, Rainer Glaschick in Germany, Bernard Sufrin in the UK (and me) have been collaborating in exploring the ‘program’. Significant progress has been made with many obscurities now illuminated. The study has directed new attention to how the several types of punched card control the internal microprograms on the one hand, and how these functions interface with the user on the other.

There has been significant archive activity. The major historical source is the Babbage technical archive held by the Science Museum. The Science Museum digitised the archive in 2012 is now preparing to provide open access to the archive. The Analytical Engine project team has been the main user of the digitised archive under special licence. In the course of the project mismatches have been identified between the digitised material and the existing printed index compiled by the late Allan Bromley and published by the Science Museum in 1991. Referencing anomalies, identification of material omitted from digitisation exercise and other structural issues have become evident. Descriptions of these have been compiled and we are working with Science Museum archivists to resolve and correct these ahead of open access release. The work is detailed and, given the volume of material, substantial. Eye-strain is an ongoing hazard.

This archive work has suggested a new and significant prospect for the role of the Notation in an understanding the designs. One of the difficulties in understanding the designs is the need to reverse engineer logical function from mechanical drawings of mechanisms - this without textual explanation of purpose or intention. The original hope was that the notations, expressed in Babbage’s symbolic descriptive language, would contain a higher-level logical description that would relieve this difficulty. As described in earlier reports the main features of the Notation were decoded from a detailed knowledge of the mechanisms of Difference Engine No.2. The provisional conclusion from that study was that the notations are a description of the mutual physical relationships of mechanical parts and are not an abstraction of a logical description of the Engine’s function. Further, that the mechanical design preceded the notational description. New material found in the archive suggests that while this might be true for Difference Engine No.2 the notations for the Analytical Engine (about 2,700 of these) may indeed embody higher-level logic, control functions for sequencing the punched cards and orchestrating the internal operations that the punched cards control. If so, the notations would provide the explanatory tool we have been looking for and the prospect of this is enough to distract one from the plight of refugees migrants and austerity, even if only briefly.

Doron Swade


  1. Hello,

    Thank you for the update, very interesting and encouraging.

    Did Plan 28 not have a mailing list, once upon a time?

    I'm sure many supporters/donors would greatly appreciate the occasional newsletter.

    Best regards,
    [email protected]

  2. Why don't your crowd source the transliteration component of understanding the images?

    You could do something similar to what existing crowd sourcing services do - whereby which people enter the text/translations that they think are accurate for what is selected in that specific square of the image.

    If you then took peoples responses - you could use the statistics around the responses to determine the most likely translation and go on from there...