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ot----fine instrument sales Fall 2019

The pictures of that watchmakers lathe really caught my eye, as I have an identical cross slide/compound assembly. I found it years ago in a secondhand store, and was so taken by the level of craftsmanship that I bought it without having any use for it. I have often wondered who the maker was, and marveled at the time that had obviously gone into its manufacture.

Paid about $40 IIRC for the cross/compound. Can only imagine what they would have asked had they had the whole lathe.

Measured the threads of the feed screws, and they didn’t seem to match any standard.

Many thanks for posting it.

John
 
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Thanks for posting this, I've only seen pictures of an ellipsograph in prints and books ~ from 1810 not surprising the reserve price is nearly $6k … At auction with two or three people really wanting it could crest over $9k.
 
I have a survey instrument called an Alanap which bears more than a passing resemblance to the Circumferentor, picture 3 in the third series of photos, though it does not have (or need) the compass. Mr Google is uncharacteristically silent on this application of the name, though he does tell you all about Alanap herbicide, and how to buy a railway ticket from Birobidzhan to Alanap, neither of which seems to be particularly relevant.

Anybody else ever heard of these? I have come across two others, both in a museum, whose staff had no idea of their purpose. Theirs were apparently designed to be mounted on a stick and lack the two level bubbles on mine, which was designed for a tripod. It originally had a plumb bob, whose outline can be seen between the two top right spokes in the view of the instrument in its case.

I believe it was used in the late 1800s/early 1900s for producing the scale outline of a paddock, whose area could then be determined using a planimeter - not my favorite instrument itself! It relied on taking fore sights and back sight from each station, then setting the angle between the previous back sight and the new fore sight by aligning the previous back sight by sighting along the fixed arm of the sighting apparatus, then moving the moveable arm to line up with the next fore sight. The sighting apparatus would then be removed from the body of the Alanap and the angle between the two sights transferred to the ongoing plot of the paddock circumference. Distances between stations were measured with a 100 link surveyor's chain. While this system dispensed with the use of a compass, it must have been slow, and carrying a small drawing board would, I suspect, have been more awkward than a compass and notebook. The sighting apparatus was also graduated to act as a scale rule.

Mine had a very fragile, incomplete and mostly illegible typed set of instructions dated 1910 in the case, obviously typed by a person familiar with the instrument to give his workmates an idea of how to use it.

The photos show 1. the components, 2. The under side, 3. The instrument in its case and 4. The instrument set up for use. Photos not in the order I intended!

franco
 

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I too am surprised at how cheaply the Whitworth micrometer sold.

I would be interested in some description of the instrument, how it was meant to be used etc. It has some similarities to the famous Whitworth 'millionth of an inch' bench micrometer but with a lot more features, some of which are a puzzle to me. I know that Whitworth sold quite a few of this type of micrometer but little beyond that. Anybody have some detailed information, or perhaps a book suggestion?
 
Bill,

See Shelley's book here:-

Workshop appliances including descriptions of the gauging and measuring instruments, the hand cutting-tools, lathes, drilling, planing, and other machine-tools used by engineers : Shelley, C. P. B. (Charles Percy Bysshe), 1827-1890 : Free Download, Borrow, and Streaming : Internet Archive

Whitworth must have quickly regretted his claim of a 'millionth', but it certainly caught the imagination of the wider public.

I hope the Whitworth measuring machine has gone to a museum.

I've seen a few examples in museums, but this one stands out for its sensitive anvil utilising a spirit level. Remarkable.

Another unusual (among the total of 4 or so machines that I've seen!) feature is that it has V-blocks to support two different sizes of workpiece, rather than just one. I should add that the workpieces were generally standard length gauges.

Whitworth originally aimed to ensure a consistent anvil force by using a 'feeler' (described in Shelley's book) inserted between the workpiece and the anvil. One of the pair of supporting V-blocks had small projecting arms to support the feeler. These can also be seen on the auction machine.
 
Whitworth originally aimed to ensure a consistent anvil force by using a 'feeler' (described in Shelley's book) inserted between the workpiece and the anvil.
Yes, I was wondering how the level was 'preloaded' . It can certainly show 'where' the anvil is , but is unable to apply a consistent force on its own. It's unlikely to be spring loaded (springs being unreliable things) . Could it be weighted perhaps?

Bill
 
Bill,

It might be pre-loaded by a spring. There's more to it than meets the eye. There appear to be two 'plungers' in the barrel, and an adjusting screw in the bronze yoke, perhaps to adjust any pre-load?

What I don't understand is that although the spirit level could detect movement with any required level of sensitivity, it does require a finite amount of movement, and how do you know much to correct the measurement by?

If only Rivett had bought it!
 
What I don't understand is that although the spirit level could detect movement with any required level of sensitivity, it does require a finite amount of movement, and how do you know much to correct the measurement by?

Presumably you just tweak until at zeroed , but given that the micrometer screw is at the far end any backward movement would need to move the DUT which would require some force for a heavy test bar (considerably more than the test shim used with the 'millionth' mic)

If only Rivett had bought it!
Let's hope someone equally knowledgable bought it , not someone wanting a steam-punk ornament!
 
Where were these sales? I follow lots of sales in the UK but missed this one. Would have bought the Whitworth in a second for that price.

rivett---sale conducted by Bonhams--I think they were disappointed with
final tally---but a few pieces appear to have had spirited bidding :)
 

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That is a nice model, but for my taste the bidding was high in comparison to the low cost of the micrometer. The latter has real engineering/historical significance, but unless I am missing something this is just a well constructed model, possibly incomplete? of which there are many examples (in UK anyway).

Very sad that the Engineerium failed. Was this the only item in the auction that came from there?
 
Back to the Whitworth measuring machine:

I recalled seeing a non-Whitworth measuring machine at Summerlee Industrial Museum, and on looking at my photos I was surprised to find that it had the same spirit-level type sensitive anvil (see photo).

I don't think the machine's maker was identified, but a bit of delving revealed that it was the Newall Engineering Co, and thanks to Grace's Guide, this led me to a description in The Engineer, 10 July 1903. See extract of drawing. The article reveals that the spirit level is graduated and the sensitivity is such that 0.001" movement of the anvil would move the bubble 4". So, that answers the questions I had.

En route to finding the maker I came across some interesting history of the Newall Group:-

FEEDBACK | NEWALL ENGINEERING – 1900 to 1988

They made precision machine tools, including jig borers. The linked page refers to a 62" swing cylindrical grinder in New Orleans which has recently been overhauled. I think the present Newall DRO business is an offshoot of the old Newall company.

JD 2019 Newall1.jpg JD 2019 Newall2.JPG
 
Cameraman, if you want to see another ellipsograph, you can follow this link to see the one made by George Wilson and one of his apprentice about 12 years ago. George is a member of this forum but I think he hasn't been very active in the last couple of years.

You can go to Colonial Williamsburg and ask to see it. There is an episode of The Woodwright's Shop with Roy Underhill where he uses the tool for reproducing some cabinet feature. I remember seeing it less than 2 years ago.

Jacques
 








 
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