The Mathematical Content of the Rough Draft on Conics

J. V. Field and J. J. Gray
Additional contact information
J. V. Field: Science Museum
J. J. Gray: The Open University

Chapter Chapter IV in The Geometrical Work of Girard Desargues, 1987, pp 47-59 from Springer

Abstract: Abstract Desargues began with the remark that lines will be supposed to contain a point at infinity, which may be reached by travelling in either direction along the line. This enabled him to treat pencils of parallel and intersecting lines on a par; a pencil of parallel lines being regarded as a pencil of lines intersecting at a point at infinity. The use of points at infinity also simplified his treatment of points in involution, as we shall see. He then unleased a plethora of botanical names for simple configurations of points and lines which, taken together, only serve to obscure the text. Of those terms, we need only say that those which connote line segments, such as trunk, branch, shoot and limb, may be taken to mean ‘line’ or ‘line segment’, whereas those which suggest points, such as knot, butt, post and stump, mean ‘point’. Then he reached his first useful term, the tree.

Date: 1987
References: Add references at CitEc
Citations:

There are no downloads for this item, see the EconPapers FAQ for hints about obtaining it.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:spr:sprchp:978-1-4613-8692-6_4

Ordering information: This item can be ordered from
http://www.springer.com/9781461386926

DOI: 10.1007/978-1-4613-8692-6_4

Access Statistics for this chapter

More chapters in Springer Books from Springer
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().