What is this scale on the compass?

July 25, 2005 3:16 PM

What is this scale on this compass (see inside)? How is it used?

On the edges of the folding cover a scale from 0 to 150 is printed. the 100 mark is exactly 1 inch from 0. There is a thin slit running the length of the scale. On the other side is a nearly identical scale and slit, only the numbers are printed upsidown (as if to be read while leaning over the compass) and it says S- instead of S+.

Note it was manufactured in Serbia.

Slope? Scale on a map? Height of an object? Were stumped, help!

posted by rubin to Science & Nature (4 answers total)

It's a clinometer - which have scales graduated in degrees from 0 to +90 and from 0% to +150% slope. Also called an inclinometer it is used in surveying for measuring angles of elevation, slope, or incline, such as an embankment.
posted by ericb at 3:25 PM on July 25, 2005

Response by poster: Thanks, There is a lot of information on using stand alone inclinometers on google.. they all seem to be like o protractor with a hanging piece... but I don't quite get what to do with this compass version. Has anyone used one like this?
posted by rubin at 3:39 PM on July 25, 2005

Is there a level on the compass, parallel to a line connecting 150 on one side and 0 on the other? Or a way to hang the compass from a string, centered on the end of the cover away from the hinge?

I'm assuming that you are to sight through both slits at a distant object while the compass is level, then put something partially over the far slit so it's just under the 0 on the near slit, then turn the compass around and read off the elevation or declension.
posted by nicwolff at 3:54 PM on July 25, 2005

Here are some fancy Finnish devices that do the same thing.
posted by Kirth Gerson at 5:40 PM on July 25, 2005