2
$\begingroup$

I found this picture.

old

An old mathematician has devised this tool. It is about conic sections.

What does it do? I can't figure out.

Maybe only Arab users can answer this question. The script is written in Arabic.

I understand some of the words such as "برکار" which means compass. And "تام" meaning universal; complete.

It seems this is designed to draw any conic section. But is that possible?


From the translation of the text in the picture, it turned out to be a universal conic section drawer compass.

Now my question is how does it do that?

the most relevant place to ask this, I think, must be here. Because here may be some people who have seen this tool once.

$\endgroup$
  • 1
    $\begingroup$ You may want to take a look at the two pictures at the bottom of this page. This question sounds more relevant to the history of math and science. Anyway, I found the persian article to be more informative (Yes, I could read it) $\endgroup$ – polfosol Jan 5 '17 at 16:14
  • $\begingroup$ @polfosol The two pictures are very small. And the Wikipedia article doesn't talk about the principle upon which this apparatus was made. I think understanding the way this thing works is more related to math rather than history of math, compatriot! $\endgroup$ – AHB Jan 5 '17 at 18:37
0
$\begingroup$

This is a compass, a device for drawing circles by rotating a pencil. The marks measure the angle of the compass (and thus the radius of the circle). The original image can be found on Wikimedia commons.

$\endgroup$
  • $\begingroup$ Just a simple compass? $\endgroup$ – AHB Jan 5 '17 at 14:59
  • $\begingroup$ Probably, that's what the description says, and I don't see any way to change the angle evenly while drawing, so it can likely only draw circles. $\endgroup$ – zzz Jan 5 '17 at 15:01
  • $\begingroup$ Why two protractors then? $\endgroup$ – AHB Jan 5 '17 at 15:02
  • 5
    $\begingroup$ Wikipedia presents it as being a "perfect compass to draw conic sections". Since an ordinary compass can't draw conic sections other than a circle, there must be more to it. References 6 through 10 in the Wikipedia article seem to lead to more detailed descriptions of it. @AHB. $\endgroup$ – Henning Makholm Jan 5 '17 at 15:03
  • 1
    $\begingroup$ My bad, the leg can indeed be moved while drawing. hal.archives-ouvertes.fr/hal-00658217/en $\endgroup$ – zzz Jan 5 '17 at 15:05

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.