Another Mystery Tool

Hi All,

Just going through last weeks auction items and found this oddity:

Comes with a couple of bundles of these copper coated rods which appear to be carbon with a small central hole all the way through.

All I can think of is some sort of carbon arc setup, looks highly dangerous if that is the case.

Help welcomed.

Cheers, Martin

Carbon arc brazing torch with cables that are too thin as usual.

Exciting to use though

Martin your spot is correct. A carbon arc brazing unit. Bring the rods steadily closer till arc commences then commence heating/brazing. Unsophisticated perhaps but works well.

I have an old XP welder, and it has similar carbon rods, which are for brazing rather than arc welding, never tried them though!

Good for giving a suntan, make sure that all exposed skin is kept to a minimum, obviously appropriate eye protection needed too.

Keller of Norwich used to market. Noel.

Definitely an arc brazing torch.

I've got one, not used all that often, Very hot so has to be kept moving, but handy when needed.

Bit if a knack to keeping the arc correct.

REALLY need to cover all bare skin, otherwise severe sun burn.

Howard

You can use them to increase the carbon content of mild steel thus making the contact area hardenable - but you also get surface "erosion".

Im with you there Noel they were sold from Kellers of Norwich on Cattle Market Hill.

Hi all,

Here are two more mystery items from the weekends car boot haul, probably from a school physics lab, not sure what they are.

They appear to be incomplete but I do not know what is absent:

Any info would most welcome!

Cheers, Martin

Last one is I think a moving coil galvanometer. Shine a light at the mirror and you can measure the angular deflection when a very small voltage is across the terminals. Connect it to a coil and plunge a magnet in and out.

I'd agree with the galvanometer, and I think the second item is a vacuum pump missing its bell jar.

Similar to this one 
https://www.bonhams.com/auctions/26661/lot/57/

I remember replying to this article on The BBC last year with some more detailed info, but I must have deleted the email now.
https://www.bbc.co.uk/news/science-environment-59562636

Bill

Edited By peak4 on 09/08/2022 19:14:26

The last item is a galvanometer. Reflected light beam for indication amplification. Low friction. Google "Galvanometer".

Willie

Hi Peak4

If a vacuum pump would there have been a bell jar on the platform perhaps on a rubbers seal?

Martin

or maybe a grease/leather seal, I'm not sure.

See my amended earlier reply too
https://www.bbc.co.uk/news/science-environment-59562636

Also include Ballistic, in your Galvanometer searches.

Bill

Edited By peak4 on 09/08/2022 19:20:52

Melted wax was also used as a seal. Used for suffocating butterflies or introducing something to kill them in the more elaborate ones.

Agree bell-jar and vacuum pump. Nice find! I expect the pump seals are leather and will need to be replaced. Plastic might work. You can still buy bell-jars, try ebay etc.

The glass bell was probably sealed with Vaseline rather than hot wax because wax was used for more permanent seals. The four experiments I remember showed:

• air is necessary to transmit sound. (A clockwork bell gradually went quiet as the air was pumped out even though the clapper is seen to be still working).
• air is necessary to combustion. (A lit candle goes out when the air is removed)
• air is necessary to life. (A mouse dies when the air is pumped out.)
• alcohol boils when the pressure is reduced even though the temperature doesn't change.

Dave

Hi All.

Many thanks for the info on these items.

The vacuum pump is now on its way to a French Instrument collector after a huge amount of interest on EBay.

Cheers, Martin

I would have said that the last one was a ballistic galvonometer. The max angle of deflection being proportional to the total charge passed.

regards Martin

Hello,

Anyone know where you can get the copper coated carbon electrodes from. I have only a couple left. I assume Kellers are no longer!

Andrew.