OneGuyFromBarlick

His magnificent beard? (Probably not asbestos, though.)

Stanley's got part of the answer - it is for a kilning process and it is rotary, hence the cogged wheels on the left. It would be about 30 foot (10 metres) long so only about half the length is seen in the photo, which might be why a gradient isn't obvious. Now for the second part of the answer - what was it used for? It was designed not for general applications but for processing a specific material. Any offers?

Yes, David, the beard is impressive. I'm surprised it wasn't considered a fire risk! I wonder if he had a very long tobacco pipe to minimise the risk?

China clay?

Right colour but wrong material, although the one in the photo wasn't that remote a distance from the china clay industry.

Barytes?

No, but you're on the right track with mineral processing. The equipment started out as a way of removing impurities from metal ore before smelting but ended up being used instead as part of an industry based on the impurity itself, which had become more valuable than the metal.

Removal of haematite from iron ore.

Could be almost anything. Arsenic from lead ore?

Both very close and Stanley has the key word, arsenic. It's an Oxland tube arsenic calciner at Devon Great Consols mine. Early on the tin ore, then copper ore, had to be calcined to remove arsenic and sulphur which otherwise would poison the smelting process. It was first done in batch mode in beehive shaped kilns but as production of ore increased they needed a continuous process. This became more pronounced when copper and tin prices fell and arsenic itself became a desirable commodity for insecticides and other uses. The mines then started calcining arsenical pyrites which had until then been considered a nuisance waste product. A furnace burns at the lower end of the tube and ore is fed in at the top. The treated ore drops out at the bottom and the arsenic and sulphur are volatilised and pass out the top end and to a chimney. A labyrinth was placed between the end of the calciner and the chimney to allow the arsenic to condense out on the walls. At intervals men were sent in to the labyrinth to scrape out the arsenic.

The photo comes from this web site: http://www.ssb.plymouth.ac.uk/labplus/s ... erview.htm
and there is more technical detail here: http://www.tvia.org.uk/pages/arsenicrefineries.shtml
where it also describes the other type, the Brunton calciner.

The lead mines around here used long flues to detached chimneys to condense lead vapour from the calcining and smelting furnaces. I've often thought that the job of scraping them out must have been incredibly dangerous. A chemist once told me that the highest concentrations of Germanium were in coal fired flues but I don't think anyone realised until the practice had almost ceased.
Try this, all right it's string but a very specific use....

No takers?

Is it something to do with sealing joints?

No. Clue, it's very strong fine nylon string.....

Is it for stitching leather.?

Sorry Gloria, no. Clue, think about using string to keep things straight....

For brickies to line up the courses?

Did it replace piano wire ?, i used to use it for lining up line shafts etc. ?

I'm with Tiz, Builders string,

You've got it, brickie's line. Useful stuff for hanging small pictures!
Next for shaving?

I have a proper mystery object, so much so I don't know what it is, it will take a bit of photographing though. I'll chuck it up later.

They're the best sort! Lets us use our imaginations. Bring it on!

...it's an invisible object. (Sorry.)

Got sidetracked, going on a bike ride now but will post it later.

Good luck with ride Ian.

Back from bike ride, through shower and right side of lunch. Here is my mystery object. Found in drawer in the building next to where the boiler house used to be on the Ouzledale side of Long Ing Mill. Building was formerly a weaving shed but used then by Ouzledale foundry then Esse the upper floor is partitioned into offices. Building has had multiple uses so the object could be from anywhere, nothing to do with it's current use of theatrical costume hire.

Sorry it's bit out of focus, the base is 2" dia with two countersunk holes for mounting, the object is 5" in length.



This is the view looking straight down



Next two show the top part in more detail