A friend of mine gave me this Starrett No. 24M vernier caliper rule.
Where it came from I do not know.
Is there a specific use for it ?

Regards
Henri

Listed in my 1938 Starrett catalog as a micrometer caliper gage, " this gage is specially adapted to the tire industry, in measuring tire molds and by affording greater scope than any tool of its kind made and is valuable in many other lines."  The metric versions were available in 30 cm, 50 cm, 60 cm & 90 cm sizes. Ranging in prices from $16.75 - $24.00. The catalog picture shows divider type of points threaded into the tips of the jaws. Other attachments were available to assist using calipers in conjunction with the tool. # 24 A is inch series and the # 24 M is the metric version.

Lewill 2, thanks for the detailed information about this interesting object.

Regards
Henri

It's strange that what would normally be the "fixed jaw" is movable on the scale. I can't imagine why that would be useful.

Joe B 

Catalog shows and mentions trammel points threaded into the ends of the jaws (tips) so maybe to zero out the one end when using that function.

Quote from: Lewill2 on February 15, 2019, 06:23:51 AM
Catalog shows and mentions trammel points threaded into the ends of the jaws (tips) so maybe to zero out the one end when using that function.

Exactly, zero out for trammel points. Plus to zero for inside measurements.

A pretty neat tool.