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<p class="MsoNormal"><span style="mso-fareast-language:EN-US">Hi Doron:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">Many thanks – and congratulations, on a truly wonderful project, and now this splendid documentation.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">Cheers<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">Brian<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Helvetica;color:black">—<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Helvetica;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Helvetica;color:black">School of Computing, Newcastle University, 1 Science Square, Newcastle upon Tyne, NE4 5TG<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Helvetica;color:black">EMAIL = Brian.Randell@ncl.ac.uk PHONE = +44 191 208 7923<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:Helvetica;color:black">URL = https://www.ncl.ac.uk/computing/staff/profile/brianrandell.html</span><span style="mso-fareast-language:EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:0cm;margin-right:0cm;margin-bottom:12.0pt;margin-left:36.0pt">
On 02/12/2023, 15:01, "Members" <members-bounces@lists.sigcis.org> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Dear All <o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">I am pleased to report that the full technical description of Charles Babbage’s Difference Engine No. 2 has recently been made available online on open access by the Science Museum (London).
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">The Engine was built to Babbage’s original drawings (1847-1849) and completed in 2002. It has 8,000 parts, weighs 5 tonnes, and works as Babbage intended. It is the first of Babbage’s calculating engines to be
built in its entirety. <o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Over the decades-long life of the project I documented the interpretation of the 19th-century drawings, the design decisions made in its construction, its assembly, operational debugging, and what was learned
from running the Engine for countless live public demonstrations. <o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">A full description of the Engine is presented in two works available online:
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Difference Engine No.2 Technical Description <<a href="https://www.sciencemuseum.org.uk/sites/default/files/2023-09/DE2_Technical_Description.pdf%3e">https://www.sciencemuseum.org.uk/sites/default/files/2023-09/DE2_Technical_Description.pdf></a>
(232 pages, 131 illustrations) <o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Provides a detailed interpretation of Babbage’s design, and documents the technical understanding that informed the successful construction of the working machine.
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Difference Engine No.2 User Manual <<a href="https://www.sciencemuseum.org.uk/sites/default/files/2023-08/User_Manual_PDF_Vsn_1.1_Final_SEC1.pdf%3e">https://www.sciencemuseum.org.uk/sites/default/files/2023-08/User_Manual_PDF_Vsn_1.1_Final_SEC1.pdf></a>
(147 pages, 199 illustrations) <o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Documents the practical procedures for operating the Engine safely, setting up a calculation, testing, trouble-shooting, fault-finding, and maintenance including lubrication.
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">The two documents are free-standing i.e. relevant drawing-excerpts are embedded in the text so that understanding does not, for the most part, rely on reference to the full 19th-century design drawings.
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Direct Browser Links: <o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Technical Description: <o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt"><a href="https://www.sciencemuseum.org.uk/sites/default/files/2023-09/DE2_Technical_Description.pdf">https://www.sciencemuseum.org.uk/sites/default/files/2023-09/DE2_Technical_Description.pdf</a> <<a href="https://www.sciencemuseum.org.uk/sites/default/files/2023-09/DE2_Technical_Description.pdf%3e">https://www.sciencemuseum.org.uk/sites/default/files/2023-09/DE2_Technical_Description.pdf></a>
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<p class="MsoNormal" style="margin-left:36.0pt">User Manual: <o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt"><a href="https://www.sciencemuseum.org.uk/sites/default/files/2023-08/User_Manual_PDF_Vsn_1.1_Final_SEC1.pdf">https://www.sciencemuseum.org.uk/sites/default/files/2023-08/User_Manual_PDF_Vsn_1.1_Final_SEC1.pdf</a>
<<a href="https://www.sciencemuseum.org.uk/sites/default/files/2023-08/User_Manual_PDF_Vsn_1.1_Final_SEC1.pdf%3e">https://www.sciencemuseum.org.uk/sites/default/files/2023-08/User_Manual_PDF_Vsn_1.1_Final_SEC1.pdf></a>
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Additional Material <o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">The Babbage Papers at the Science Museum: <<a href="https://collection.sciencemuseumgroup.org.uk/documents/aa110000003/the-babbage-papers%3e">https://collection.sciencemuseumgroup.org.uk/documents/aa110000003/the-babbage-papers></a>
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">* Digitised archive of Babbage papers including full technical archive and Notebooks.
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<p class="MsoNormal" style="margin-left:36.0pt"><a href="https://collection.sciencemuseumgroup.org.uk/documents/aa110000003/the-babbage-papers">https://collection.sciencemuseumgroup.org.uk/documents/aa110000003/the-babbage-papers</a> <<a href="https://collection.sciencemuseumgroup.org.uk/documents/aa110000003/the-babbage-papers%3e">https://collection.sciencemuseumgroup.org.uk/documents/aa110000003/the-babbage-papers></a>
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Charles Babbage’s Difference Engines and the Science Museum | Science Museum <<a href="https://www.sciencemuseum.org.uk/objects-and-stories/charles-babbages-difference-engines-and-science-museum%3e">https://www.sciencemuseum.org.uk/objects-and-stories/charles-babbages-difference-engines-and-science-museum></a>
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">* Short contextual and historical summary.
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<p class="MsoNormal" style="margin-left:36.0pt">* Links to the Technical Description and User Manual are in Further Reading.
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<p class="MsoNormal" style="margin-left:36.0pt"><a href="https://www.sciencemuseum.org.uk/objects-and-stories/charles-babbages-difference-engines-and-science-museum">https://www.sciencemuseum.org.uk/objects-and-stories/charles-babbages-difference-engines-and-science-museum</a>
<<a href="https://www.sciencemuseum.org.uk/objects-and-stories/charles-babbages-difference-engines-and-science-museum%3e">https://www.sciencemuseum.org.uk/objects-and-stories/charles-babbages-difference-engines-and-science-museum></a>
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<p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Citation: <o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Swade, Doron, Charles Babbage's Difference Engine No. 2: Technical Description. Science Museum, 2023.
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<p class="MsoNormal" style="margin-left:36.0pt">Swade Doron, Charles Babbage's Difference Engine No. 2: User Manual. Science Museum, 2023.
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<p class="MsoNormal" style="margin-left:36.0pt">Best wishes <o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:36.0pt">Doron Swade <o:p></o:p></p>
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