A 17th century mathematician invented a device that was generally used to measure quantities in shops until well into the 20th century. Who was he and what property made his device special?

TMCMONK

Is it Charles Babbage, inventor of the first automatic digital computer? LET ME KNOW~! Jun 05 07, 9:22 PM

lanfranco

I have to wonder whether this is the slide rule, attributed to William Oughtred, who invented a circular slide rule and combined two devices invented by Edward Gunter that allowed for multiplication and division: http://www.oughtred.org/history-new.shtml See also the Wiki site "Slide Rule". Jun 05 07, 9:26 PM

queproblema

I'd go with a balance scale, but need to research it. Jun 05 07, 9:34 PM

queproblema

Since I can't readily find any meat scale or such significantly improved over ancient ones, I'll sit back and watch this one. Will it be a scale? a yardstick? an eyedropper? a noggin? It would help to know what kind of shop. General, haberdashery, milliner, grog? Jun 05 07, 9:52 PM

gmackematix

I'm not here to be helpful, Que. :) Still you're almost there, once you've researched it of course! Jun 06 07, 12:36 AM

Arpeggionist

The slide-rule was the invention. So now the inventor... I'm going to make a very wild guess and say... Leibniz? Jun 06 07, 1:35 AM

Baloo55th

Oughtred invented the slide rule, based on an invention by the Laird of Merchiston. Better known as John Napier, he devised a calculating aid known as Napier's Bones and invented logarithms as well. Oughtred invented both circular and linear slide rules, according to http://www.maxmon.com/1600ad.htm Jun 06 07, 2:58 AM

gmackematix

I'll agree, Frankie, that the slide rule is an answer that almost fits the question, but weren't slide rules used to do calculations rather than to measure quantities. Queproblema is there in that it is a type of balance scale I am after. We just now need the name of its inventor and how this scales was an improvement on its predecessors. Jun 06 07, 3:46 PM

queproblema

We're not supposed to guess, but since gmack's not here to be helpful :) I'm guessing it's a butcher shop and he's talking about a spring scale. Robert Hooke was a 17th-century mathematician, inventor, and otherwise very smart guy, who is famous for his work with cells. (At least I think of cells when I think of Hooke.) If he didn't invent the spring scale, he could have, and should have, for my purposes today! He did formulate a law of elasticity that bears his name. Check under "Career" at this link: http://en.wikipedia.org/wiki/Robert_Hooke This one has an animated Slinky and a lab lesson: http://inventors.about.com/library/inventors/blsprings.htm Jun 06 07, 4:04 PM

queproblema

Oh, hi, gmack! I started answering and then had a phone call and a pop-in visitor. If it's a BALANCE scale I'm wrong. . . Jun 06 07, 4:10 PM

gmackematix

On balance, yes. I will help a bit by saying the mathematician was a Frenchman. Jun 06 07, 8:05 PM

queproblema

How about Gilles de Roberval's balance? The objects being weighed didn't have to be in the middle of the pans. http://www.lhup.edu/~dsimanek/museum/roberval.htm Jun 06 07, 10:54 PM

gmackematix

That tips the scales in favour of a yay for you, Que! Roberval was a mathematician who worked out areas between curves and volumes between curved surfaces using limits before the ideas of the calculus were published and has a series of curves named after him. His scales have been used in shops (and labs) ever since. Jun 07 07, 12:34 AM