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der5997

Museum Research Question

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Hi, I've a question on the use of insulators we have in our museum's collection.

We have two. These are small white ceramic, with a hole in the top presumably for accommodating a fixing nail.

Both have U.S.A on the top together with similar, but not identical makers marks.WIS-P AND WIS-P-C

Here's a couple of photos:

2003-002-002_zpsd2f1eb55.jpg

and the underside:

2003-002-002base_zps026329c0.jpg

Any help you could give me in identifying the system these were used for would be helpful. They were recovered in 2003 from the inside of a building that had been a pool hall among other things in the village of Sheet Harbour, Nova Scotia. That building had been disused for some years. The electrical distribution system in Sheet Harbour was installed around 1923 as a by-product of the opening of a Ground-wood Pulp Mill at that time.

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Those insulators look like a common outdoor pole insulator. The wire wraps around the insulator.

All the knob and tube I've seen, including this inspection from yesterday, the knob is two pieces and the wire is 'clamped' by the knob.

Click to Enlarge
tn_201433019321_2014-03-29%20085.jpg

55 KB

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Electrical Inspection of Dwellings by Douglas Hansen has more info on that wiring method if you're interested.

Shown in your photo is a 'solid knob'. Other components used in this system are the 'split knob' and the 'tube'.

Marc

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Both solid and split porcelain knobs were used for securing interior wiring. The split knobs are the more common in residential. The solid knobs required securing the wire with and additional wire twisted on and wrapped on the opposite side of the knob. It was short lived as the split-knob installation was much quicker.

Click to Enlarge
tn_2014330212949_knobs.jpg

44.16 KB

According to the Pub, Insulators: Crown Jewels of the Wire, The knobs in the OP were manufactured by the Wisconsin Porcelain Co. in Sun Prairie, WI.

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Those insulators look like a common outdoor pole insulator. The wire wraps around the insulator.

All the knob and tube I've seen, including this inspection from yesterday, the knob is two pieces and the wire is 'clamped' by the knob.

Click to Enlarge
tn_201433019321_2014-03-29%20085.jpg

55 KB

Thanks, but these are one-piece, there's no detachable top with which to clamp the wire. Interesting photo though, do you mind if I use it when writing up the "Narrative" for these insulators?

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They're insulators for knob and tube electrical wiring systems.

More images & info on those systems here:

https://www.google.com/#q=knob+%26+tube+wiring+images

http://en.wikipedia.org/wiki/Knob_and_tube_wiring

Thanks, but the tubes look longer and thinner that our insulators, and the squat ones you show are two piece, while ours are one piece. Any thoughts?

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Both solid and split porcelain knobs were used for securing interior wiring. The split knobs are the more common in residential. The solid knobs required securing the wire with and additional wire twisted on and wrapped on the opposite side of the knob. It was short lived as the split-knob installation was much quicker.

Click to Enlarge
tn_2014330212949_knobs.jpg

44.16 KB

According to the Pub, Insulators: Crown Jewels of the Wire, The knobs in the OP were manufactured by the Wisconsin Porcelain Co. in Sun Prairie, WI.

Bingo! That looks like the solution - and thanks for the Manufacturer info as well. May i quote you in my "Narrative" for these insulators?

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Looks like a knob for knob and tube wiring. The two-piece knobs seem to be more common. These were installed by running the wiring tangent to the groove and then a second piece of wire was wrapped around the groove and twisted onto the other wire at each side.

This link may be of interest.

http://www.docstoc.com/docs/159676740/T ... rchaeology

thanks, and I'll read that .pdf later - it's lunch here now LOL

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Nice knobs, but where's yer tubes? [:)]

LOL - stuck in the joists I expect! If I ever get access tot hat buildnig again I'll take a look - now I know what I'm looking for.

Thank you all for this excellent information.

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I have a nice knob and tube collection in the basement that I used for classes. I could be persuaded to donate it to someone that could use it!

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I have a nice knob and tube collection in the basement that I used for classes. I could be persuaded to donate it to someone that could use it!

Les, that's indeed an interesting prospect. If you are so inclined, just one "Tube" would complement our two item collection. If you happen to have any provenance to accompany the tube you select, so much the better. (Age, Manufacturer, Location the tube was used in, that sort of thing.) We have very little available display space - these insulators sit on a shelf in our Museum Promo section next to the Visitor Information Centre. That section is house din what used to be a broom closet - so you maybe get the idea!

If this Forum does Private Messages, PM me and we can push this forward. Do you have a PayPal account? If so you could invoice me - Postage and so - delivery address, those details. [:-thumbu] If not, I do have a $US account and could cut you a cheque.

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Both solid and split porcelain knobs were used for securing interior wiring. The split knobs are the more common in residential. The solid knobs required securing the wire with and additional wire twisted on and wrapped on the opposite side of the knob. It was short lived as the split-knob installation was much quicker.

Click to Enlarge
tn_2014330212949_knobs.jpg

44.16 KB

According to the Pub, Insulators: Crown Jewels of the Wire, The knobs in the OP were manufactured by the Wisconsin Porcelain Co. in Sun Prairie, WI.

Bingo! That looks like the solution - and thanks for the Manufacturer info as well. May i quote you in my "Narrative" for these insulators?

Sure.

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I have a nice knob and tube collection in the basement that I used for classes. I could be persuaded to donate it to someone that could use it!

Les, that's indeed an interesting prospect. If you are so inclined, just one "Tube" would complement our two item collection. If you happen to have any provenance to accompany the tube you select, so much the better. (Age, Manufacturer, Location the tube was used in, that sort of thing.) We have very little available display space - these insulators sit on a shelf in our Museum Promo section next to the Visitor Information Centre. That section is house din what used to be a broom closet - so you maybe get the idea!

If this Forum does Private Messages, PM me and we can push this forward. Do you have a PayPal account? If so you could invoice me - Postage and so - delivery address, those details. [:-thumbu] If not, I do have a $US account and could cut you a cheque.

will pm you and you feel free to pm me

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Bingo! That looks like the solution - and thanks for the Manufacturer info as well. May i quote you in my "Narrative" for these insulators?

Sure.

Much appreciated Bill,

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