Description

Eighteen sheets of instruments and related geometry.  From Denis Diderot’s (1713-1784) famous Encyclopédie ou dictionnaire raisonné des sciences, des arts et des métiers (Encyclopedia or Systematic Dictionary of Sciences, Arts and Trades), commonly called the Encyclopédie.   It was published in increments during the period 1751 to 1772.  Supplements were published in 1776 through 1780.  Image size approximately 8” w x 13”h on sheets 10 ¾”w x 16 ½”h.
 
Astronomie [Astronomy].  Eight sheets, sequentially numbered:  “Suppl. Pl. 1 [through 8]”, showing astronomical instruments and related spherical geometry.  Engraved by Benard.
 
Gnomonique [Gnomon – (Dialing)].  Six sheets (Plates 2-7) related to telling time by the use of shadows.  Most of the instruments are illustrated in their inclined position to show that latitude must be considered when measuring time by the sun.  Included are geometric figures illustrating how the devices were showing time. 
 
The original meanings of “dial” were “sundial” and “clock dial”, from Latin dialis = “pertaining to or belonging to Jupiter” or “of one day”, because of its use in telling the time of day.  Today the term often refers to mechanical devices such as sundials, clock dials, or the circular display of clocks and watches.  The term “dial” is also used for a circular display device in radio, measuring instruments, etc.   Even “dial a telephone number” comes from the dial on rotary phones until the advent of the keypad. Engraved by Benard.
 
Géographie [Geography].  Three sheets showing globes, globe gores, and related spherical geometry.  Drawn and engraved by Benard.
 
Navigation.  One sheet(“Pl. 1.”)showing instruments and related spherical and plane geometry.  Drawn by Groussier.  Engraved by Benard.
 
CONDITION: Slightly toned. Edges of margins irregular. Drawings good.
 
 
Z8P07