From: Dag Asheim <dash>
Subject: SUMMARY: Recent construction of Babbage's computer.
Reply-To: Dag Asheim <dash@ifi.uio.no>
Organization: University of Oslo, Norway
Date: Tue, 7 Apr 1992 17:57:25 GMT
Originator: dash@kyrre.ifi.uio.no

In article <CMM.0.90.2.702140710.dash@bera.ifi.uio.no> I wrote:
>A while ago there was some talk about the recent construction of one
>of Charles Babbage's machines.  I didn't save the thread, and now I
>need to know:
>	what was built (The Analytic Engine?),
>	when it was completed (if it is),
>	where it located today (a museum?) and
>	where can I get more information about this.
>I'll summarize if I get any answers and at least one me-too.

The steady stream of answers seem to have stopped, so it is time for a
summary (even though I didn't get any me-too's).  First I have to
thank all who responded:

	Douglas W. Jones <jones@pyrite.cs.uiowa.edu>
	David Shepherd <des@inmos.co.uk>
	Peter Thompson <thompson@inmos.co.uk>
	Malcolm Shute <mshute@cs.man.ac.uk>
	ccwillia@tesla.uwaterloo.ca
	ijp@doc.imperial.ac.uk
	uad1077@dircon.co.uk
	Robin Fairbairns <Robin.Fairbairns@lsl.co.uk>
	aki@cruzio.santa-cruz.ca.us (Aki Korhonen)
	cory@enigami.MV.COM (Cory Kempf)

Thanks!  Here is the short summary:

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>	what was built (The Analytic Engine?),

Babbage's second difference engine.  But see the answer from Douglas
W. Jones below for other Babbage (re)constructions.

>	when it was completed (if it is),

Largely done sometime last year (to celebrate Babbage's 200th birthday).

>	where it located today (a museum?) and

The National Museum of Science and Industry ("The Science Museum"),
Exhibition Road, South Kensington, London.

>	where can I get more information about this.

Doron Swade, Senior Curator (Computing and Control)
Science Museum, Exhibition Road, London SW7 2DD
Telephone 071 938 8181 Fax 071 938 8118
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Here is the long summary:

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From: Douglas W. Jones <jones@pyrite.cs.uiowa.edu>

> A while ago there was some talk about the recent construction of one
> of Charles Babbage's machines.  I didn't save the thread, and now I
> need to know:
> 	what was built (The Analytic Engine?),

              Babbage's son built a prototype of the Analytical Engine.  This
              is now in the science museum in London.  It didn't work very
              well (it tended to jam), but it was used to compute at least
              one table of logarithms.  It included a reduced precision
              version of the mill (ALU), with only a few registers.  It was
              hand cranked.

              The Science Museum has built Babbage's second difference
              engine (the one he never finished).  That was largely done
              sometime last year, but it tends to jam.

              There is a group today in Australia that is interested in
              building a full-scale version of the analytical engine.  One
              of Babbage's sons moved to Australia, taking many of his papers
              there, and these have fired the enthusiasm of people in the
              CS community there.

If you read Babbage's "Reflections on the Life of a Philosopher" you will
find that a Swedish book publisher (mathematical tables?) was so inspired
by Babbage's description of his difference engine in the Edinburough Journal
(or some such publication), that the publisher had a difference engine built.

This Swedish difference engine was exhibited in Paris, and later sent to the
US naval observatory in Albany (according to Babbage).  The British were
impressed, and had a copy made that was put into production use to compute
actuarial tables.

What became of the Swedish publisher?  Did any modern manufacturer of
calculators descend from that venture?  Was the machine shipped to the US
put to any interesting uses?  Did any of the late 19th century calculator
manufacturers in the US get ideas from that machine (NCR and Burroughs come
to mind).

I know that a difference engine was used to compute a table of mathematical
functions that was published in 1910.  The preface to that table included
a 10 page description of how the difference engine was used to compute the
table.  The preface did not cite Babbage, but it included a photograph of
the engine used (a hand cranked engine with printed output).  The engine
was made in Germany; was it mass produced?  How was it descended from
Babbages work?

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From: David Shepherd <des@inmos.co.uk>

>	what was built (The Analytic Engine?),
yes
[The consensus is "The Difference Engine".  -dash]
>	when it was completed (if it is),
last summer
>	where it located today (a museum?) and
science museum, london
>	where can I get more information about this.
i'd expect that the science museum have something.

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From: Peter Thompson <thompson@inmos.co.uk>

The Science Museum in London (England) built a complete, working Difference
Engine. I went to see it recently and it was quite impressive; however I think
it will be displayed better in a while, when the museum have finished
re-organising their computer section. They're trying to raise money to build
the printer, which would be about as big again.

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From: Malcolm Shute <mshute@cs.man.ac.uk>

>	what was built (The Analytic Engine?),
No, the Difference Engine
>	when it was completed (if it is),
In the last 12 months, I think
>	where it located today (a museum?) and
The Science Museum, Exhibition Road, South Kensington, London
>	where can I get more information about this.
The Science Museum, Exhibition Road, South Kensington, London

--------------------------------------------------------------------------

From: ccwillia@tesla.uwaterloo.ca

Hello,

I didn't see the discussion on comp.arch about the difference engine, but
I can tell you a little bit about it as I saw it last fall in London.  It
was on display at The National Museum of Science and Industry in London.
The following information comes from a pamphlet I picked up when I was
visiting.

"Difference Engine No. 2, designed between 1847 and 1849, was built to 
original designs from materials closely matching those available to 
Babbage...  A complete set of design drawing survive though no attempt
was made to build the machine until now....

Difference Engine No. 2 was designed to tabulate the value of 7th order
polynomials to 30 decimal places...  Difference Engine No. 2 is a decimal
digital machine...

The engine is a research machine built to investigate the thesis that
Babbage's designs were sound but that the machines could not be built
because of limitations of Victorian mechanical engineering...

For further information contact:
Doron Swade, Senior Curator (Computing and Control)
Science Museum, Exhibition Road, London SW7 2DD
Telephone 071 938 8181 Fax 071 938 8118

--------------------------------------------------------------------------

From: ijp@doc.imperial.ac.uk

If I recall correctly these are the answers to your questions (don't
take any of this as being fact, my memory isn't too good :-( )

I think it was 'The Analytical Engine' [The consensus is "The
Difference Engine".  -dash] that was created and I think it was
completed some time last year. It was (and probably still is) in the
'Science Museum' (London, just round the corner from here I am now in
fact). As for more information, err. You could try writing to the
Science Museum - don't know their address, but it'll be something like
:

The Science Museum,
Exhibition Road,
London SW7

(the SW7 part is a guess) but I don't know if there's a department you
should write to, etc. 

I hope this has been of some help

--------------------------------------------------------------------------

From: uad1077@dircon.co.uk

The Kensington Science Museum in London built a complete Difference
Engine to celebrate Babaage's 200th birthday.  The finished project
is now on display there.  The only cheat is that it is driven by a
hand crank instead of by a steam engine:-).  The next project is
the automatic printer, and after that, just maybe, the Mill of the
Analytic Engine.

--------------------------------------------------------------------------

From: Robin Fairbairns <Robin.Fairbairns@lsl.co.uk>

>	what was built (The Analytic Engine?),

No.  I think it was one of the difference engines.

>	when it was completed (if it is),

Last year, as I recall.

>	where it located today (a museum?) and

In the Science Museum, Exhibition Rd., South Kensington, London, UK.  It
was actually them that did the construction. 

>	where can I get more information about this.

The Science Museum publishes a booklet about it, of which I've heard 
good things said, though I haven't myself seen it.  Try writing to 
them... (as far as I know they're not on the net, qua institution, 
though they're almost next door to ic.ac.uk)

>I'll summarize if I get any answers and at least one me-too.

I hope this helps...

--------------------------------------------------------------------------

From: aki@cruzio.santa-cruz.ca.us (Aki Korhonen)

The machine was the Difference Engine 2.  It was built in Britain and
I believe it's at the "National Science Museum" (not really 100% sure 
about the name,  but I believe that was it).

No,  they did _NOT_ build the analytical engine.  That would have been
quite big and way too expensive.

Oh well.

--------------------------------------------------------------------------

From: cory@enigami.MV.COM (Cory Kempf)

I am trying to remember this from a brief newspaper article I read
a few weeks ago.  

I think that it was built in a museum in the UK (london?).  It cost
more than most supercomputers, and they didn't have enough money to
build the printer (I have a dim recolection that they would need an
additional $7M)

It Worked.

It could do 7 things at once, but I think that the things were 
addition/subtraction.

That is about all I remember.


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Dag Asheim					dash@ifi.uio.no
Department of Informatics
University of Oslo, Norway
Newsgroups: comp.arch