I have had this scale kicking around my tool box for ages. I acquired it from an older gentleman who was retiring from the trade (Pattern Making). Over the years i have asked different tradesman if they knew what kind of scale it was and don’t think i ever got a satisfactory answer. I call it a scale, but i really don’t know if that’s even correct.
There’s some pretty sharp folks here in Knots so i thought i’d toss it out and see if anyone knew. Sorry for the poor quality shots, it has some markings on it that i could describe if need be.
Jeff
Replies
I don't know what it is, but am pretty sure it's an antique.
If you don't use it, and can part with it, post it for sale on eBay. It's probably worth a lot of money.
(Last year my father-in-law sold a wooden slide ruler on eBay for $800. He bought it in the late 1950s when he enrolled at Lehigh University, and it sat in his closet since graduation.)
That's what we in the industry call a thingy-dingy.
<sorry, I can resist this stuff>
No seriously, would it have something to do with transoms or complex angles?
Have no clue but as a guess I think it might have been used for scaling thangs? But I only learned about thangs in here from Mr. Froe, who has been mysteriously absent of late..........
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Edited 5/7/2008 3:38 pm ET by KiddervilleAcres
Since he was a pattern maker I would guess that its a shrink scale. The sloped lines corresponding to different rates of shrinkage. That it's made of wood and is folding seems to be contrary to that idea though. And since your name here indicates that you are also a patternmaker that would indicate you would recognize a shrink scale when you saw one. So, its obvious that I'm not laying any money on my guess.
Well, as i said, i do not know either. It isn't made of wood though, my guess is ivory (and obviously brass) or at least maybe what they used to make piano keys from because it has the same hue and patina that we have all seen on old pianos and organs.On one side at the ends, there is engraved an L S C and on the other side a S T T Perhaps the L S C could relate to Leg, Segment and Chord, but that's just a guess. It's not a shrink rule.We are often calculating Draft angles, but that is so easily done with algebra (calculator or not) or a sine table i can't see the value of having an instrument like this. It does have a small divot in the center brass boss where it seems a compass or divider point has been swung from, and yet no tell tale arc swing markings that would seem to go with it. The cover of one of the recent Lee Valley catalogs has some similar "thingy's" on it, but mostly wooden folding rules and etc. That's what reminded me of this.In any event, i won't be using it to pry open varnish cans anytime soon.Map and Chart making perhaps?No biggie, as i said, Iv'e had it kicking around for a couple decades, it can kick around for a couple more.
Hi Jeff,I believe what you have is an instrument called a sector. There was an article about sectors in FWW some years back, and there is a brief description of them in "Blackie & Son's" _The Victorian Cabinet-Maker's Assistant_. Having never seen a sector in person, I haven't studied the description enough to be very clear about how it is used. But the description includes the information that the L S C scales refer the line of Lines, the line of Secants and the line of Chords. Likewise, the S T T scales refer to the line of Sines and two lines of Tangents. There may also be a line marked P or Pol for polygons. The description indicates there may also be some logarithmic scales.I'm not sure the text contains enough detail to truly learn how to use the sector from it, but I'd be happy to pass it along to you in an e-mail message if you'd be interested.I just found this online information which covers much of the same information:http://www.sliderules.info/a-to-z/sector/sector.htmDon McConnell
Eureka Springs, AR
Edited 5/8/2008 1:10 am ET by chamfer
Great answer.. I read it all and as confused as ever!
I was thinking it was a Angle 'thingi' used by the builders..
About 2,550 B.C., King Khufu, the second pharaoh of the fourth dynasty, commissioned the building of his tomb at Giza.
Don, Thank you, it is exactly that, a Sector, and what a fascinating instrument it is. The link you included opened a path for me to enjoy. When i was an apprentice, i purchased a gentleman's tools as he retired and this instrument was in one of his boxes. That was in about 1978, or 1979 he was in his 70's then. I remember him coming from a family of tradesman and many of his tools were hand made. He was a crackshot Patternmaker as well as a good fella to work with. At that time many of the old timers were still reluctant to share their knowledge of the trade, Colonel (his name) was not like that. I have no need or desire to part with the instrument, but i am interested in it's value. Thank you once again, i figured Knots was the place to pose that question and i wasn't disappointed.Regards,Jeff
Way cool. I'd love to play with one. They are, in short, geometric analogue computers.
Joe
Is it some sort of ruler that has something to do with the golden ratio? Thats my guess
Jeff
Pretty neat peice of history there. I am sure most of the old pattern makers used tools like this often instead of going to the drawing board to figure out segments and staves. Now we do it on CAD but I am not sure if it is quicker, but is more accurate. I have been in a lot of shops and met a lot of fellow pattern makers over the years but this is a new one for me. It would be neat to learn how to use it.
Rich
The Professional Termite
Heya Rich, I also had asked many people what they thought it was. Now that i have been shown what it is i am fiddling around with it with the aid of some printed out instructions. Quite a versatile little gadget and I'd agree with you as to how useful it would have been in its day. Segments for sure, scaling up (or down) a model from a print comes to mind. Keeping the proportions in line would be aided by it. The older i get, the more fortunate i feel that i got a nice heavy dose of the old school before everything went to computers and CAD. Although I am pretty sure I'd swap a Sector for a seat of Solid Works or Mastercam without much thought about it. <grin>Jeff
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