Oddly enough, now a small plethora of info on spur gearing. I was out
looking for gristmill output figures in 17th century mills for
comparative purposes and found a web publication on Exeter Mills which
had a paragraph on Cricklepit Mill that stated "In 1689, one of
Cricklepit's wheels used a treble mill gearing system to drive two
millstones, one of which was grinding malt by 1689."
Your colleague is quite right then. If it goes back from 1723 to 1689,
what's the consensus on how early it was actually invented?
Have you any info on when metal gears were first used and then a date
by which they were in general use, regardless of tooth type?
I can probably access the drawing if you would be so kind as to
provide the web address. The one I have is from a 1980's Xerox and is
not exactly the clearest item.
Thanks,
Lyle Browning
On Nov 3, 2008, at 9:15 AM, Peter King wrote:
> Thank you.
>
> I asked a colleague in the Midlands Mills group about this. He
> pointed to
> his own booklet on Warwickshire watermills, which reproduces the same
> illustration. This in turn enabled me to see a reproduction of the
> original
> (and associated text) in Desaguliers, J. T. (John Theophilus). A
> course of
> experimental philosophy. By J. T. Desaguliers, ... The third edition
> corrected. London, 1763. 627pp. Vol. 2 of 2 (2 vols. available):
> plate in
> vol II opposite p.452. I accessed this via 18th century collections
> on-line, which requires an Athens (or other) log in, so that I will
> not give
> a web address.
>
> The mill illustrated would now be known as Nuneaton Mill in north
> Warwickshire. He said that this is merely the first illustration of
> multiple stone nuts. He believes there are earlier examples. It
> was an
> invention, but nobody is certain quite when.
>
> Peter King
> 49, Stourbridge Road,
> Hagley,
> Stourbridge
> West Midlands
> DY9 0QS
> 01562-720368
> [log in to unmask]
>
>
> -----Original Message-----
> From: Arch-Metals Group [mailto:[log in to unmask]]On Behalf
> Of
> Lyle E. Browning
> Sent: 30 October 2008 23:41
> To: [log in to unmask]
> Subject: Re: Hybrid gears
>
>
> On Oct 30, 2008, at 5:07 PM, Peter King wrote:
>
>> My colleagues in the Midland Mills Group (mostly interested in corn
>> mills)
>> regularly say that wooden teeth were preferred, even with metal
>> machinery,
>> because they were easily replaced. Mishandling the mill could
>> easily strip
>> several teeth, so that it was desirable to have something that could
>> easily
>> break and be replaced, thus preventing worse damage.
> I've seen small pieces out of teeth, but in the main, the hybrid parts
> are stacked up under the stone floor and the all-metal set-ups were
> doing the actual work. But, that was before I was aware enough to
> differentiate the stages and none that I saw had markings anyway.
>>
>>
>> What is your 1723 reference? I had heard of the change to driving
>> several
>> stonenuts off the same great spur wheel, but I had seen a source
>> pinning the
>> change down.
> The 1969 "Transactions of the International Symposium on Molinology,
> held in Denmark. Chapter 27 was on Great Britain and was entitled The
> Water-powered Cornmills of England, Wales, and the Isle of Man, A
> Preliminary Account of their Development by David H. Jones. In that,
> page 311 has the relevant part. A 1723 drawing by Henry Beighton of
> the mil at Barr Pool by the Abbey in Nunn Eaton, Warwickshire was
> cited as the first to show spur gearing. The drawing, in the pub,
> shows two sets of stones with one wheel. The two are powered off two
> separate lantern/pinion sets. The author's take on it was that it was
> referred to as something new and different.
>
> Lyle Browning
>
>
>>
>>
>> Peter King
>> 49, Stourbridge Road,
>> Hagley,
>> Stourbridge
>> West Midlands
>> DY9 0QS
>> 01562-720368
>> [log in to unmask]
>>
>>
>> -----Original Message-----
>> From: Arch-Metals Group [mailto:[log in to unmask]]On Behalf
>> Of
>> Lyle E. Browning
>> Sent: 30 October 2008 16:00
>> To: [log in to unmask]
>> Subject: Hybrid gears
>>
>>
>> Spur gearing is generally recognized as being invented in 1723
>> allowing the 1 wheel to 1 device problem that had plagued mills from
>> the get-go to disappear. There was a transitional hybrid period where
>> the wheels were metal and the teeth were wood. Then it all moved to
>> totally metal gearing.
>>
>> Was the transition from wooden lantern/pinion gearing to hybrid
>> metal/
>> wood to all metal a result of incremental steps from the familiar to
>> the new a result of the then presumed inherent brittleness of cast
>> iron or was it a stepwise progression based on the known and workable
>> system? The problem was in if one bought a cast wheel with teeth
>> and a
>> tooth broke, you had to replace the entire wheel, so better to have
>> wooden teeth that if one broke, then the tooth could be replaced.
>> This
>> was standard on wooden gear systems.
>>
>> Wooden transmissions used lantern/pinion systems. A secondary thought
>> was that the move to metal started by using metal for the wheels as
>> it
>> was cheaper and more durable. Wood was used for the teeth because
>> they
>> had to mesh with the wooden lantern. Is this a reasonable
>> supposition?
>>
>> In my surveys of gristmills, I see examples of hybrid wheels under
>> the
>> stone floor as they were replaced by all metal bevel gears, but which
>> were kept for various reasons.
>>
>> At some point in the 19th century, the hybrids stopped and the all
>> metal gears took over, at least here in VA and elsewhere in the US
>> that I have managed to find info concerning. When do all metal bevel
>> gears start?
>>
>> Were there advances in iron casting that would allow for all metal
>> wheels with teeth and bevel gears to replace the hybrids?
>>
>> In short, can metallurgical advances be shown to parallel the
>> transition from wood to hybrid to metal? Or are we looking at a
>> conservative step-wise progression for which cast metals already
>> existed that would work that the millers and other power applications
>> were slow to adopt?
>>
>> Any thoughts gratefully received.
>>
>> Lyle Browning
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