Discussion:  All Topics 
Topic:  whiteboard compass 
Post a new topic to the General Discussion in Geometry discussion 

Subject:  RE: whiteboard compass 
Author:  patb 
Date:  May 29 2005 
http://www.pballew.net/etyindex.html under the term compass
Compass  Many students wonder why the name of the instrument used to draw
circles, and the navigational aide used to find directions share a common name.
The origin of both words is from the use of a compass to mark off a length. The
Latin word passus means step, and a compass was used to mark off equal steps.
Later the French extended the meaning to include any act of measuring off by
steps. For navigation these steps were often around a circle used to measure the
direction from North, and the object used to measure was the magnetic needle and
a floating card that marked of equal steps around a circle, called a compass
card. Eventually the card, needle, and all were addressed with the single word,
compass. The English extended the idea to other circular references, and then to
a general idea of inclusion or surrounding with words such as encompass and
compassion.
In earlier times the mathematical compass was called a "compasses" using the
plural, and each leg was considered a compass. It seems the mathematical term
made it into English first, "The mathematical instrument so called from 1387.
The mariners' directional tool (so called since early 15c.) took the name,
perhaps, because it's round and has a point like the mathematical instrument.
The word is in most European languages, with a mathematical sense in Romance, a
nautical sense in Gmc., and both in Eng. " [from the Online Etymology
Dictionary]
 
Post a new topic to the General Discussion in Geometry discussion  
Visit related
discussions: Geometry  