Peter - Thanks for this, and hold everything chaps, two developments.

OA have produced a plan of 1842 that shows a boiler in pretty much the 
right location with ?? water pipes going through the wall behind the 
boiler into a chamber that appears to be producing heated air 
distributed to each prison cell on four floors of the wing.  How could 
we have overlooked this? Unless things change substantially that's what 
the boiler was doing.

Without seeing the photos, Rob Kinchin Smith suggested it was a `wagon 
top boiler', but tells me that the top is not in fact the right shape, 
and would have needed a reservoir for steam.  As I understand it he is 
thinking it has to be a water boiler therefore, and is saying that some 
support for the later date would be if the bolts are hexagonal as 
opposed to square.

If you don't hear from me for a week or so, someone feel free to remind 
me and I'll update the list.  Thanks to all. - Brian

In message 
<[log in to unmask]>, 
Peter King <[log in to unmask]> writes
>I am no expert on this area, which is why I refrained from replying earlier:
>1. a boiler for a steam engine for use at the prison in the 1780s seems
>highly improbable.  Steam engines were until that decade solely used for
>pumping.  (Except for certain pirates), all non-pumping engines up to 1800
>were made by Boulton & Watt; I believe the identify of all of them is known,
>and does not include Oxford Prison.
>2. What would steam-power be used for during construction? The only
>possibility that I can think of is a hoist, but
>a. There is no evidence stream engines were thus used
>b. The contractor would surely have set it up in a way that would enable it
>to be removed at the end
>3. It therefore seems much more likely that it was for the provision of hot
>water for some purpose.
>4. One of the replies refers to the possibility of steel pipes.  That is
>certainly wrong.  Steel was not a readily available material and only used
>for certain quite specialised purposes in the early 19th century.  If a
>ferrous material was in use it would be iron, quite probably cast iron,
>though I understand wrought iron pipes were made in Birmingham in the 1820s
>using much the same technique as for musket barrels.  Was any of the pipe
>work saved?
>
>Peter King
>
> -----Original Message-----
>From:   Industrial Archaeology [mailto:[log in to unmask]]  On Behalf Of
>Brian Durham
>Sent:   08 February 2004 20:00
>To:     Peter Wickham King
>Subject:        Saddle-shaped boiler at Oxford Prison.
>
> << File: signature.asc >> Paul - Belated thanks for your comments and refs
>to Bourne (1861 edn)
>and Stephenson, et al (1829) and your second message yesterday
>suggesting the Boulton & Watt Collection (deposited in Birmingham
>Central Library.
>
>I have indeed had several very helpful replies from Ind Arch and am
>copying this back to the list.
>
>a)  Boiler pre-dating the prison?  The boiler is so integrated with the
>1780s structure it cannot reasonably be older, and the historic maps of
>the castle show no building anywhere near this.
>
>b)  Boiler providing steam power for construction?:  I think if the
>boiler had related to construction it would have been installed in a
>more accessible position.
>
>c)  Boiler for a steam powered water pump?  This could be, assuming it
>was a steam generator,  but the obvious water source is at the opposite
>corner of the prison beside the river, with tanks surviving in adjacent
>St George's Tower, and a capstan arrangement designed to use a different
>power source (i.e. the prisoners).
>
>d)  Boiler for a laundry? Jason Lucas was first to suggest this, because
>he felt this was a water boiler rather than steam generator.  He
>referred me to Dr. Eleanor Casella at the University of Manchester, and
>I'm hoping to hear from her.  It looks promising because the later
>laundry is on this side of the range.  John Ferris notes `Water boilers
>didn't start appearing until after c1820, before then they were usually
>steam at low pressure, about 5psi', but this could still give it up to
>50 years operation before abandonment in 1868.
>
>However John Ferris asks `Are we sure it is a boiler and not a warm air
>stove', and I have to say that the bore size of the (?Inlet) pipe seems
>extravagant for water (see photo, use hand-shovel for scale, maybe
>75-100 mm bore).  But the Victorian prison has hot air ducts of massive
>scale (1 m square section), and this pipe looks puny by comparison.
>Perhaps after all it is about right for a water-hearing system using
>convection circulation?
>
>Two questions have been raised which I can't answer from memory, so I
>will need to consult with the site staff.
>
>1)  Pat Achon asks was the "external" tubing made from steel/bronze/ are
>they soldered ?  any more tubing present around the boiler ?
>Provisionally I think a lot of this went as the general contractor was
>digging out upper part of the vault, before the significance of the
>boiler was recognised.
>
>2)  Jason Lucas points out that some indication whether the boiler was
>original may come from how the connecting pipe-work goes through the
>masonry, i.e. if there is evidence of hacking through it is more likely
>to have been a later installation.
>
>Thanks again to all.  Incidentally for those of a stronger constitution
>there is a forthcoming `Meet the Ancestors' programme on a different
>aspect of the Oxford Castle work, which may briefly show the hanging
>cell next door, though filmed before the boiler was discovered.  Said to
>be BBC2 16 Feb, but I can't find confirmation on the Beeb website.  -
>Brian
>--
>Brian Durham ([log in to unmask])
>also Oxford City Council ([log in to unmask])

-- 
Brian Durham ([log in to unmask])
also Oxford City Council ([log in to unmask])