Anyone Know what this Old Draftsman or Engineering Tool is Called?

Question

http://i277.photobucket.com/albums/kk80/besunny/Draftingtool.jpg

I thought at first it was an old compass, but both spokes are solid metal. The little turn wheel adjusts how far apart the spokes stand.

It was made (stamped on metal) by L.S. Starrett Co, of Athol, Mass. (They spell out the state like that, so it looks like the 1950s or earlier.)

What was it used for?

Answer 1

Its proper name is a pair of dividers.

Answer 2

I think it is a caliper.

It was used to measure distances or transfer that measurement.

Answer 3

Numbat,

finally an engineer answers correctly!

Cheers m'dear, JJ

Answer 4

It is called a divider and is still in use.  On a scale drawing or map, the divider is used to measure off distances.  It is held at the top and walked along a line on the drawing.  The tool is also still in use for navigation.  It is used in a similar manner to walk off distances on a scale map.

Answer 5

Old but not ancient. It's not a draughtsmans tool at all but would be used by a fitter. It's a divider. It's used to transfer measurements from a scale to work.

<>http://catalog.starrett.com/catalog/cata...

Answer 6

Divider

Used to "mark off" equal distances on a drawing

Answer 7

Yes, it's called a caliper as the first poster mentioned.  Back in the day when all mechanical drawing was done by hand and design engineers had their own drafting set, all good sets had a caliper.  You would use them to measure small parts or components on existing drawings.

Answer 8

It is called a divider, It is used  in geometrical drawing.