double parallel rule, rumbographe
Date1850-1870
Inventory Number5260
ClassificationParallel rule
Subject
Maker
Schiavetti Belliéni
fl. 1840 - 1870
Cultural Region
Place of Origin
Dimensionsrule: 1 × 44.5 × 11.5 cm (3/8 × 17 1/2 × 4 1/2 in.)
case: 3.5 × 47 × 14 cm (1 3/8 × 18 1/2 × 5 1/2 in.)
case: 3.5 × 47 × 14 cm (1 3/8 × 18 1/2 × 5 1/2 in.)
Material
DescriptionThe parallel rule is stored in a rectangular mahogany case that opens with two brass hinges along one of the long edges. There are two metal hooks attached to the front panel of the case that hook onto two metal pins in the front of the lid to keep the case closed. The inside of the case is unfinished. There are two, small cylindrical attachments inside the lid, and a black-painted platform to support the compass of the instrument.
The parallel rule consists of three, rectangular dark wooden strips. They are connected by two brass triangle hinges. Each hinge consists of two, pivoting brass arms proceeding from the central rule to each of the outer rules. The hinges and pivots are placed such that the distance between the rules can be increased up to the length of the arms and reduced to nothing while keeping the rules parallel.
The outer two rules are thinner than the central one, which is actually made of two strips of wood fixed together. A silver and brass compass and protractor emerges from one end of the central rule. It is constituted of a fixed brass disc with a rotating, circular, silver plate on the top. A smaller, hollow brass circle in the center acts as a view hole for placing the compass accurately on the surface below, and the spool for a brass arrow. The arrow is fixed in place while the silver face plate can rotate beneath it. There various scales engraved in the silver plate and base brass disc. First, a compass roses consisting of sixteen directions (each of the four directional quadrants further subdivided into four) is engraved in the silver plate. Also on the silver plate are four 90° scales. Nord (North) and Sud (South) are labeled 0. Est and Ouest (East and West) are labeled 90. The scale increases in tens to 90 in both directions from Nord and Sud. The same engraved set of four 90° scales in engraved around the circumference of the base brass disc. The brass arrow is fixed such that it points to 90° on the circumference of the base brass disc. The silver plate rotates beneath the arrow such that the scale alignment is variable.
The parallel rule consists of three, rectangular dark wooden strips. They are connected by two brass triangle hinges. Each hinge consists of two, pivoting brass arms proceeding from the central rule to each of the outer rules. The hinges and pivots are placed such that the distance between the rules can be increased up to the length of the arms and reduced to nothing while keeping the rules parallel.
The outer two rules are thinner than the central one, which is actually made of two strips of wood fixed together. A silver and brass compass and protractor emerges from one end of the central rule. It is constituted of a fixed brass disc with a rotating, circular, silver plate on the top. A smaller, hollow brass circle in the center acts as a view hole for placing the compass accurately on the surface below, and the spool for a brass arrow. The arrow is fixed in place while the silver face plate can rotate beneath it. There various scales engraved in the silver plate and base brass disc. First, a compass roses consisting of sixteen directions (each of the four directional quadrants further subdivided into four) is engraved in the silver plate. Also on the silver plate are four 90° scales. Nord (North) and Sud (South) are labeled 0. Est and Ouest (East and West) are labeled 90. The scale increases in tens to 90 in both directions from Nord and Sud. The same engraved set of four 90° scales in engraved around the circumference of the base brass disc. The brass arrow is fixed such that it points to 90° on the circumference of the base brass disc. The silver plate rotates beneath the arrow such that the scale alignment is variable.
Signedprinted in center of trade label inside case lid: Fabrique d'Instruments / SCHIAVETTI BELLIÉNI / OPTICIEN DE LA MARINE / Rue d'Aiguillon, 19, Brest. / Mathématiques, Marine, Géodésie, Dessin, / Astronomie, Metèorologie, Photographies.
printed around a printed medal on left-hand side of trade label inside case lid: OPTIQUE / Médaille de Bronze 1845 / Seul dépositoire / des / Instruments de / E. LORIEUX / S[illegible]es, Sextants / Octants, horizons / artificiels. / Rumbographes. / Déposé.
printed around a printed medal on right-hand side of trade label inside case lid: PHYSIQUE et CHIMIE. / Médaille d'Argent, 1849. / Longue-vues, Jumelles, Baromètres, Thermomètres / Aréomètres, Boussoles- / Maxime, Micromètres. / Fait la réparation, / et échange les / Instruments. / Planisphères de Keller.
engraved around circumference of brass extension: PAR SCHIAVETTI BELLIENI. OPTICIEN A BREST. RUMBOGRAPHE LORIN.
FunctionParallel rules facilitate the drawing of parallel lines of variable distance apart. This is a double parallel rule since the central rule is always parallel to each of the outer rules. The distance between the central rule and each outer rule need not be the same. The compass and protractor attached to the central rule enables navigational use. The compass can be aligned with the compass rose of a map such that distances and angles can be measured, or drawn.
ProvenanceDavid P. Wheatland purchased from Alain Brieux, Paris, May 6, 1965 (lot 22/2900). Donated to CHSI in April 1977.
Charles W. Dixey
Date: circa 1830
Accessories: silver framed green shagreen case
original curatorial cards and photos
Object number: DW0288
Elliott Brothers
Date: circa 1863
Accessories: wooden case; bill of sale and the dealer's tag, in the instrument's file
Object number: DW0489
T. and T. Blunt
Date: circa 1820
Accessories: rectangular sharkskin covered wood case
Object number: DW0712
Gebrüder Haff
Date: circa 1960
Accessories: black storage case
two white cards with conversion tables inside case
Object number: 1997-1-2000
George Adams (I)
Date: circa 1766
Accessories: original case
Object number: DW0955
Elliott Brothers
Date: circa 1890
Accessories: rectangular mahogany case
Object number: DW0745
Captain David Thomson
Date: circa 1816
Accessories: documentation in instrument file
Object number: 1996-1-0010
English
Date: 1775-1800
Accessories: case contains the following nine instruments: one ivory and brass sector; one ivory and brass parallel rule; one brass protractor; two pairs of dividers, one with pen holder, pencil holder, and inking wheel (for drawing dotted line) attachments; and pen.
Object number: 5458
Wood-Regan Instrument Company, Inc
Date: 1930-1950
Accessories: wooden storage case
Object number: 1995-1-0001
Peter & John Dollond
Date: 1780-1800
Accessories: mahogany box with brass hooks, hinges, and handle; tripod (see 5240b)
Object number: 5240a
See also/See also
