Compasses

From Inventions

(Difference between revisions)
Jump to: navigation, search
Line 35: Line 35:
|categoria_1= Measuring instruments
|categoria_1= Measuring instruments
-
|categoria_2= Drawring instruments
+
|categoria_2= Drawing instruments
|categoria_3=  
|categoria_3=  
|categoria_4=   
|categoria_4=   

Revision as of 10:56, 13 November 2009

Since Renaissance times synonymous of seste (compasses), the name derives from the Latin "cum" and "passus", literally "with step", that is, at a measured or constant rhythm.


Description

Instrument for drawing circles, ellipses and other curved lines. Also instrument of measurement and for transferring measurements. The term "compass" or "compasses" denotes a wide range of instruments for drawing, measurement, and proportional calculation. Besides the more common compasses for drawing circumferences, widespread since antiquity, the Renaissance has left us a great number of special compasses, whose names reflect their specific functions: oval compasses to draw ellipses, hyperbolas and parabolas; two-point compasses — also called dividers — to divide lines and transfer measurements; single-handed dividers, to track routes on sea-charts; compasses with curved points, called Caliper compasses, to measure mouths of cannons, cannon balls, and columns; three-point compasses to reproduce maps; four-point compasses, or reduction compasses, to enlarge or reduce drawings, divide lines and circumferences proportionally, and draw polygons; eight-point compasses to measure fractions of degrees and carry out proportional calculations; proportional compasses to perform arithmetic, geometric, and trigonometric calculations and to measure weights, gradients, and distances for military use; and sophisticated surveying compasses that combined a magnetic compass, a windrose, and optical sights for surveying and for drawing topographic maps.


Bibliographical Resources

Scamozzi, Vincenzo. L’idea della architettura universale, Venezia 1615, Parte I, Lib. I, Cap. XV, p. 49: "…I compassi siano piuttosto d’ottone, che d’altra materia che s’irrugginisca; ben leggieri e sottili di gambe, purchè non tremino, all’uso di Francia…".



Images


Author of the entry: Filippo Camerota

Personal tools
Categories
In other languages