Unusual Go-No Go Tool?

[Martin King 2Participant @martinking2]

BTW is that a helix on the parallel brass part of the point?

Martin

[pgk pgkParticipant @pgkpgk17461]

If you don't like silly stories then don't read this.

It's 1854, 15 years after Charles Goodyear invented ebonite. The coalition forces are fighting Russia in the Crimea. We're in the T&SD dept of the War Office. Great Grandad Q is briefing Grandpa Bond:

"This machine can be taken apart and concealed in a mere cabin trunk. To use it you charge up these Leyden jars by rubbing your amber cane across the silk. Once charged you need to be certain that the voltage is accurately calibrated. Place the micrograph controller around the print area and clip the hole upon the stylus tip in it's retracted position. If you only see a spark when the indictator is in the GO position then it's ready. If not then you may have to discharge the jar to the needed level.
Once adjusted place one of the thin wafers of ivory into the print area and lower the stylus to the writing position. Wind the clockwork spring that controls the on-off contact, set it spinning, switch on and you can now use the pantograph to trace your message in micrography."

pgk

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Martin King 2 on 21/08/2021 18:30:20:

BTW is that a helix on the parallel brass part of the point?

Martin

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It’s a scuff mark from the ‘wiper’ contact … pitch matches the screw thread.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Martin King 2 on 21/08/2021 18:29:20:

[…]

Just wondering if there are is any small melted pitting on the inside which would support the arc idea? ie sparks?

[…]

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I need to investigate this very carefully … not sure how fragile that plastic might be.

As you can see; the heavy marks are on the area where the plastic sleeve is contacting the ebonite body.

It will be tricky to look at the interior surface of the ‘window’ areas, but I’ll give it a go.

MichaelG.

[Robert Atkinson 2Participant @robertatkinson2]

It is almost certainly a breakdown voltage tester. A lower voltage version of this:

http://www.lasertools.co.uk/Product/5655/Adjustable-Spark-Tester

But I can't figure out what it was connected to or the scale units.

Robert G8RPI

[Robert Atkinson 2Participant @robertatkinson2]

Thinking some more I came to magneto tester, possibly on the primary circuit. I then found this webpage:
https://www.themagnetoguys.co.uk/test-equipment
see the wooden handled spark gap abut 1/3 down the page.

My only other thought was testing the early medical type shock machines. That might explain the odd measurement units.

Robert G8RPI.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Robert Atkinson 2 on 21/08/2021 22:11:13:

Thinking some more I came to magneto tester, possibly on the primary circuit. I then found this webpage:
https://www.themagnetoguys.co.uk/test-equipment
see the wooden handled spark gap abut 1/3 down the page.

My only other thought was testing the early medical type shock machines. That might explain the odd measurement units.

Robert G8RPI.

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Thanks, Robert

… I think revelation might eventually come if we can ever find any reference to MICROGRAPHS as a unit of measurement.

I know what micrographs are ; and to date, I have failed to find any other use of the word.

MichaelG.

[Jon LawesParticipant @jonlawes51698]

I tried to dive in deeper to the use of the word Micrograph, and even the earliest use of the term says they are to do with Photographs taken through a microscope or by similar techniques. But in the earliest editions of Merriam Webster it also lists this version which I was unaware of:

"an instrument for measuring minute movements by magnifying and recording photographically the corresponding vibrations of a diaphragm moving in unison with the original object"

[Michael GilliganParticipant @michaelgilligan61133]

That’s further away from the standard definition than I have ever seen, Jon

… you may be onto something [‘though I’m not exactly sure what]

MichaelG.
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A good working definition for modern usage is that a micrograph is a representation of a microscopical view.

We then have a sub-set called photomicrographs, where the medium is photographic.

[Michael GilliganParticipant @michaelgilligan61133]

… and on this page, Jon’s new-found definition gets top-billing : **LINK**

https://medicine.en-academic.com/32911/micrograph

I need to find some details of these instruments

MichaelG.

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and … as if by magic: Nineteen pages from 1911

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2124883/

 I  now need some coffee !

Edited By Michael Gilligan on 23/08/2021 07:42:51

[pgk pgkParticipant @pgkpgk17461]

Another Link for you

https://www.mayoclinic.org/tests-procedures/mohs-surgery/about/pac-20385222

[Michael GilliganParticipant @michaelgilligan61133]

My search in Cornell’s library was a little disappointing: **LINK**

https://www.cornell.edu/search/?q=micrograph+polygraph#

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Thanks, pgk

If my reading is correct, then Moh’s micrographic surgery simply involves the use of microscope imaging to confirm that the cancerous tissue has been fully excised .. so I don’t think this gets us any further towards understanding the device.

If I’ve missed some important point, please do let me know.

MichaelG.

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[quote]
Mohs surgery is a precise surgical technique used to treat skin cancer. During Mohs surgery, thin layers of cancer-containing skin are progressively removed and examined until only cancer-free tissue remains. Mohs surgery is also known as Mohs micrographic surgery.

[Graham MeekParticipant @grahammeek88282]

Hi Michael,

I have tried "Micrographs" as a company, as 100 and 300 Micrographs being a unit of measurement. I have tried it as a "Pocket type current setting device", as well as voltage. Putting "vintage" or "antique" into the search does nothing either. The searches assume that one is looking for a device to buy or information about Micrographs, ie pictures.

A real enigma this one.

Regards

Gray,

[SillyOldDufferModerator @sillyoldduffer]

Pondering if it's a spark voltmeter (electrostatic, not power) I looked up the formula in hope it would match Michael's graph of the instrument's scale.

The formula is:

kV = 3 * air_pressure * spark_length + ¹·³√spark_length

Although it contains an exponent, ¹·³√, I don't believe the formula curve matches the instrument.

And if it's a spark device, I agree with Michael's comment – 'seems like an accident waiting to happen.'

Possibly 'Micrograph' is a reminder, 'this tool belongs with the micrograph', and isn't the name of the tool itself or a tradename. Another meaning of micrograph is an instrument for making small engravings, though I don't see how electrostatics would play a part in that. Some sort of scale reducing Xerox machine maybe?

Dave

[pgk pgkParticipant @pgkpgk17461]

Posted by Michael Gilligan on 23/08/2021 08:51:22:

Thanks, pgk

If my reading is correct, then Moh’s micrographic surgery simply involves the use of microscope imaging to confirm that the cancerous tissue has been fully excised .. so I don’t think this gets us any further towards understanding the device.

If I’ve missed some important point, please do let me know.

MichaelG.

That was my take on it too but I did wonder whether the actual surgery was just thin skin planing or some other technique since cutting cancerous tissue always risks cells breaking off into circulation It would be possible (not sure if applicable here) to use fine wires to plane and cauterise then again the tissue cells would be too distorted to identify. There is a method of using a radio frequency cutting tool that leads to far less tissue distortion but that is bound to post date your gizmo. Quite fun to use if one got the settings right from destroying an abnormal eyelash hair follicle to slicing through an abdomen.
Link

https://www.medicalexpo.com/prod/ellman-international/product-68342-606351.html

pgk

[pgk pgkParticipant @pgkpgk17461]

SOD

.You're starting to sound like great grandad Q..

pgk

[Martin King 2Participant @martinking2]

"A real enigma this one"

Perhaps used for pushing down the keys on a coding machine?………

Hat, Coat etc….

Martin

[Keith PetleyParticipant @keithpetley53472]

Michael,

Just thinking out loud here….

…but if Micrographs isn't the maker's name then the device has no maker's info or serial number etc. which suggests that it may have been made 'in-house'. In that case a "graph" could be informal in-house jargon. For example, "100-300 micro grays per hour" is not an outlandish scale.

Keith (who knows nothing about radiation measurements, except what Google just turned up)

[Graham MeekParticipant @grahammeek88282]

I have just been looking at Martin's original pictures again.

The lettering looks to have been engraved and the "C" does not look quite right to me, Suspecting it might be a badly formed "G". The wax or white paint filling may have come out of the lettering.

Doing a search for MIGROGRAPH did to my surprise show some results, but again to do with electron microscopes.

I have yet to discover what a MIGROGRAPH is other than a miss typed word, but for there to be 10 pages in the search I cannot believe that there would be many hits for a miss spelling.

Regards

Gray,

[pgk pgkParticipant @pgkpgk17461]

Promising:
The linked article is dated 1911 and describes a new instrument for detecting minute motions of a diaphragm with applications for physiology and physical science.
Unfortunate that the full article is members/subscription only
I know Michael found similar links but this may be one of the first…
Link

https://jamanetwork.com/journals/jama/article-abstract/438880

pgk

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Graham Meek on 23/08/2021 17:47:11:

I have just been looking at Martin's original pictures again.

The lettering looks to have been engraved and the "C" does not look quite right to me, Suspecting it might be a badly formed "G". […]

.

Nice try, Gray … but inspection under the stereomicroscope confirms the letter to be C

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

This one's for you, Gray

[ click ^^^ for larger image ]

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MichaelG.

[SteviegtrParticipant @steviegtr]

I'm still thinking old magneto tester. Remove screw cap from spark plug. Insert through square hole & through the small hole. Screw cap back on the plug with H.T cable attached to it. Back off the insert to not go side. Start magneto & slowly screw the shaft in until the plug sparks. Which the H.T would at some point when the brass pointer gets close enough to let the spark jump across it.

Steve.

[duncan webster 1Participant @duncanwebster1]

But the pointy thing would be aimed at the ceramic,

[Author]

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