One of the uses was for gunnery. The English professor of Astronomy Edmund Gunter , made a sector and wrote the book Description and Use of the Sector , first published in His sector included scales of logarithmic numbers , sines, and tangents. They also provided tools for trigonometry tangent, sine, and secant and for navigation rhumbs and longitude.
Ultimately three styles of sectors, that differ by the sets of scales on the legs, evolved and are referred to as the Italian, English and French sectors.
The English sectors evolved following the design by Gunter and by had additional logarithmic scales as may be seen in the image below. The French sectors, besides the Galilean lines, included lines for determination of the weight poid des boulets and calibre size of artillery shots calibre des pieces.
Ancient History. Pompei proportional compass. MAN, Naples. National Archelogical Museum of Naples. Image from Ruggieri, Sectors in Codex Atlanticus. Antonio de Sangallo Compass notes. Tartaglia's Gunnery quadrant. Tartaglia's triangulation instrument use. Mordente's second compass ca. Mordente's third compass, Fabrizio Mordente compasses. Courtesy of Adler Planetarium, Chicago illinois. Mordente type multipoint compas. Inventory no. Oddi text on proportional compasses.
Commandino type proportional compass. Guidobaldo type compass from G. Gallucci, "Della fabrica et uso di diversi strumenti Guidobaldo type compass showing radial lines from C.
Other 16th century Instruments. Military compass of C. Bianchini's compass. Cole compass. Orsini's compass. Thomas Hood book. Thomas Hood's sector. From his description. Galileo Galilei's proportional compass. Museo Galilei. Galileo Galilei's compass instruction manual. The Galilean sector is made up of :two legs, held together by a round disk pivot , whose faces front and back are engraved with various scales; the quadrant, graduated with four scales, which is fixed by means of wing nuts to the holes in the compass legs; the clamp, a cursor inserted into one of the compass legs, which kept the instrument vertical and could serve as an extension for the leg to which it was attached.
Their primary function is that of indicating the sides of the squares whose areas are the indicated numbers. Thus the distance from the centre of the compass to each of the indicated numbers represents the square root of that number; the stereometric lines , marked with numbers up to , and indicate the sides of the cubes whose volume is the indicated number. Thus the distance from the centre of the compass to each of the numbers indicated, equals the cube root of the numbers shown.
Galileo produced several examples of his compasso. During the seventeenth century the sector became one of the most widely used mechanical calculators for scientific purposes. It comprises three parts:. As an instruction manual for purchasers of the compass, and to establish his priority for the invention, in Galileo published from his own house in Padua, printed by Peitro Marinelli, Le Operazioni del Compasso Geometrico et Militare in an edition of only sixty copies. To avoid having the compass pirated, Galileo had no illustrations of the device included in the pamphlet, which may be considered the first "computer manual.
The priority for the instrument's invention was claimed by the Milanese Baldassarre Capra in a work published in Padua in Galileo replied effectively to Capra's claims with a peremptory Difesa [Defense]. The compass, initially kept in the Uffizi Gallery, was transferred in the mid-nineteenth century to the Tribuna di Galileo. The birth of Venus Depicts same location.
0コメント