Anyone run across a ruler like this one?

[Jim Belair]

Just picked up this little boxwood rule. Seems to be for mapwork as it has a couple of distance scales, protractor and various listings and formulae for horizontal equivalents for various vertical intervals, etc. No makers mark but owner scratched in "J. Keane RCE" Royal Corps of Engineers perhaps? Great condition save a couple of corner chips.

336670

336671

336672

[glenn bradley]

Never seen one but, that is awesomely cool.

[Malcolm Schweizer]

Te scale of horizontal equivalents is for aiming a weapon up or down a hill. This likely was used with field artillery or naval weaponry.

[Jim Koepke]

I have seen the scale as in the third image on framing squares for picking off hundredths of an inch with a compass or divider.

jtk

[Mel Fulks]

I especially like the accuracy, ...refers to metric as "foreign". ....And they're off ,wheeee!!!

[Lenore Epstein]

Te scale of horizontal equivalents is for aiming a weapon up or down a hill. This likely was used with field artillery or naval weaponry.
Malcolm's explanation makes sense.

What a cool little thing, though. It almost looks hand made using some kind of hand-set type. How long is it? Any makers mark?

[george wilson]

I have not tried to investigate these scales. But,I have a similar ivory one in a very old architects drawing set. I used it in the film on spinet and violin making to lay out the keyboard of the spinet. I don't mean to infer that this was its specific use originally.

[Jim Belair]

I agree, Malcolm's explanation makes sense. The rule is about 6" long, again, no maker's mark. It does look like hand set type.

Thanks to the Internet I found....

"RCE" is Royal Canadian Engineers (the Brits were "CRE" Corps of Royal Engineers)

Of the foreign scales, the sajen and verst are obsolete Russian measurements, outlawed in about 1930 when the metric system was introduced. Similarly the Japanese and Turkish measurements are obsolete. So it likely dates to WWI. I'm no historian but thought Canada's role in the Great War was "only" in Western Europe.

[Jim Koepke]

Of the foreign scales, the sajen and verst are obsolete Russian measurements, outlawed in about 1930 when the metric system was introduced. Similarly the Japanese and Turkish measurements are obsolete. So it likely dates to WWI. I'm no historian but thought Canada's role in the Great War was "only" in Western Europe.

Thinking ahead?

Maybe they thought they might have to work with captured maps?

jtk

[Patrick Chase]

I agree, Malcolm's explanation makes sense. The rule is about 6" long, again, no maker's mark. It does look like hand set type.

Thanks to the Internet I found....

"RCE" is Royal Canadian Engineers (the Brits were "CRE" Corps of Royal Engineers)

Of the foreign scales, the sajen and verst are obsolete Russian measurements, outlawed in about 1930 when the metric system was introduced. Similarly the Japanese and Turkish measurements are obsolete. So it likely dates to WWI. I'm no historian but thought Canada's role in the Great War was "only" in Western Europe.

Militaries tend to plan for many possible contingencies (witness for example the US "War Plan Red (https://en.wikipedia.org/wiki/War_Plan_Red)" in the inter-war years). It seems safe to assume that the markings on the ruler correspond to the world's major powers at the time it was made.

Japan was definitely reckoned a serious power and likely opponent after the Battle of Tsushima (https://en.wikipedia.org/wiki/Battle_of_Tsushima), in which they decisively defeated an existing major power (Russia). They may have been so reckoned in the aftermath of the Sino-Japanese war of 1894-95.

The presence of Turkish markings probably places it before the fall of the Ottoman Empire, which happened at the end of WWI.

[Patrick Chase]

Thinking ahead?

Maybe they thought they might have to work with captured maps?

jtk

Military engineers were/are expected to be able to work with captured/foraged materials.

[Bill Houghton]

Now all you need is a cannon.

[Frank Drew]

Terrific, Jim, thanks for posting the photos.

[Andrew Pitonyak]

Wow, that is in really good condition. It is very cool!

[Jim Belair]

Terrific, Jim, thanks for posting the photos.

Glad to. And thanks for the input all.

Guess this thread turns out to be not exactly WW related.

[Josh Nelson]

I've never seen one of those in such a good condition but as has already been guessed, that is a topography rule for field artillery fire. What distinguishes it from a naval ruler of the same type is that it doesn't have a wave height conversion.

[Jim Koepke]

Guess this thread turns out to be not exactly WW related.

It is a wooden ruler after all.

jtk

[Jim Belair]

Here's a response I got from the Canadian Military Engineers Museum:

I believe that a better name would be High Explosive Protractor. The measures it converts to Imperial are Metric (French), Russian, Japanese and Turkish. During the Great War Russia, France and Japan were allied with the UK and Ireland while Turkey (Ottoman Turkey) was allied with the German and the Austrian Empires.

I would say this probably does date to the 1910's. I do not have any information on J. Keane.

[Luke Dupont]

Wow. To my knowledge, it's been quite a long time since RI (里) was a common-place form of measurement in Japan. Everyone knows it's a measurement akin to a mile or kilometer, of course, but I don't think the average person would be able to tell you how far that is.

According to Wikipedia, Japan switched to metric in 1924. So, it's likely to be prior to that.

[Jim Belair]

OK, OK, back to the ruler...

If anyone is interested, here's a link to similar rules, protractors, navigation aids in wood, ivory, brass and other materials. Again, not wood working but some are wood.

http://www.mathsinstruments.me.uk/page35.html

My source for this link was a reply to similar thread I started on the Canadian WW Forum.

[Pat Barry]

OK, OK, back to the ruler...

If anyone is interested, here's a link to similar rules, protractors, navigation aids in wood, ivory, brass and other materials. Again, not wood working but some are wood.

http://www.mathsinstruments.me.uk/page35.html

My source for this link was a reply to similar thread I started on the Canadian WW Forum.
Very interesting link. All those specialized devices are amazing. Its hard to fathom that the old timers could effectively make do with instruments such as these and now we can barely figure out what many of them may have been used for.

[Keith Outten]

Ladies and Gentlemen,

Please get back on topic and give our Moderators a break, there are way to many deleted posts in this thread.

[steven c newman]

Well, as a former Arty Forward Observer ( 13F 20 ) I would guess that this would be used with captured maps, to plot Counter-Battery Fire.

IF I'd find such a map laying around, I could use it and that scale, to plan "Fires"

For those that took"Military Map Reading", this is nothing more than another "Protractor" to read maps with.