ediograph
Datecirca 1860
Inventory NumberDW0518
ClassificationPantograph
Subject
Maker
Elliott Brothers
1853 - 1916
User
Arthur T. Walmisley
Cultural Region
Place of Origin
Dimensionslarge central crosspiece: 9.2 × 87 × 15.2 cm (3 5/8 × 34 1/4 × 6 in.)
case: 12.7 × 91.5 × 15.7 cm (5 × 36 × 6 3/16 in.)
case: 12.7 × 91.5 × 15.7 cm (5 × 36 × 6 3/16 in.)
Material
Accessoriesoriginal mahogany storage case
trade card from William D. Hocker, Inc
two original curatorial cards
DescriptionThe ediograph consists of three square brass bars: one thick central bar and two thinner bars. Each thin bar runs through sleeve fixed to the bottom of a brass wheel attached to one extremity of the main bar. Each wheel has a screw pin at the top that can be loosened to permit the thin bar to slide back and forth through the sleeve. The thin bars have incremental markings engraved on their topmost surface. There is a rectangular hole on the top of each wheel through which those markings can be viewed. There is a further set of increments engraved on each wheel just underneath the rectangular hole permitting more precise placement of the thin bars relative to the main bar.
The main bar itself runs through a sleeve fixed above a brass disc. Unlike the end-wheels, the disc is below the bar, sitting on the surface below. The main bar has engraved incremental rulings along a side face, and these are visible through a rectangular hole in the sleeve through which the main bar slides. There is a further set of incremental engravings underneath this rectangular hole.
Each of the end-wheels on the main bar has a groove around the circumference. There is a long band that runs around both wheels, fixed in the grooves. The band is partitioned in two, with brass attachments at each of the ends permitting it to be closed into an elliptical shape around the wheels. The middle section of each half of the band (the sections that sit on the circumference of the end-wheels) is flat, black rubber. This section becomes thinner and round as it approaches the brass connecting ends. The main sections of the band run parallel to the main bar.
There is a brass stylus attached to one end of one of the side brass bars (call this bar A). There is a brass attachment at the opposite end of the other side bar (call this bar B) to which users can attach a writing instrument.
There is a thin white string that runs from a loop above the brass stylus, through a loop above the wheel attaching bar A to the main bar, along the main bar, through a loop above the wheel attaching bar B to the main bar, and ending at a loop above the brass writing utensil attachment.
The ediograph is stored in a long, rectangular, mahogany box. The lid is attached to the bottom part of the box by three hinges along a long edge of the rectangle. There is a metal key hole on the outside of the bottom half of the box. There are two metal hooks on the front of the bottom of the box that fit into loops on the outside of the lid to keep the box closed.
There are several wooden inserts lined with green felt used to hold the various parts of the instrument in place inside the box. The instrument has to be disassembled before storage. The two thinner brass bars can be slid completely apart from the main bar and they are fixed in holders attached to the inside of the lid of the box. The white string remains attached to the thin bars and so is stored in the lid of the box. The main brass bar sits in the bottom half of the box, with the main central brass disc in the center and the end-wheels at opposite ends of the box.
The main bar itself runs through a sleeve fixed above a brass disc. Unlike the end-wheels, the disc is below the bar, sitting on the surface below. The main bar has engraved incremental rulings along a side face, and these are visible through a rectangular hole in the sleeve through which the main bar slides. There is a further set of incremental engravings underneath this rectangular hole.
Each of the end-wheels on the main bar has a groove around the circumference. There is a long band that runs around both wheels, fixed in the grooves. The band is partitioned in two, with brass attachments at each of the ends permitting it to be closed into an elliptical shape around the wheels. The middle section of each half of the band (the sections that sit on the circumference of the end-wheels) is flat, black rubber. This section becomes thinner and round as it approaches the brass connecting ends. The main sections of the band run parallel to the main bar.
There is a brass stylus attached to one end of one of the side brass bars (call this bar A). There is a brass attachment at the opposite end of the other side bar (call this bar B) to which users can attach a writing instrument.
There is a thin white string that runs from a loop above the brass stylus, through a loop above the wheel attaching bar A to the main bar, along the main bar, through a loop above the wheel attaching bar B to the main bar, and ending at a loop above the brass writing utensil attachment.
The ediograph is stored in a long, rectangular, mahogany box. The lid is attached to the bottom part of the box by three hinges along a long edge of the rectangle. There is a metal key hole on the outside of the bottom half of the box. There are two metal hooks on the front of the bottom of the box that fit into loops on the outside of the lid to keep the box closed.
There are several wooden inserts lined with green felt used to hold the various parts of the instrument in place inside the box. The instrument has to be disassembled before storage. The two thinner brass bars can be slid completely apart from the main bar and they are fixed in holders attached to the inside of the lid of the box. The white string remains attached to the thin bars and so is stored in the lid of the box. The main brass bar sits in the bottom half of the box, with the main central brass disc in the center and the end-wheels at opposite ends of the box.
Signedengraved on main support disc: ELLIOTT BROS LONDON
engraved on brass plaque on storage box: ARTHUR T. WALMISLEY
FunctionThe ediograph is a kind of pantograph, designed to prevent the instrument supports from dragging over the image. As such, the instrument is balanced on the center brass disc for support, without direct supports near the writing implement attachment. Most pantographs have at least four points of intersection mediating the motion of the stylus and the writing utensil. The ediograph makes use of the tension and constraints of the white string and the elliptical band to compensate for this instrument’s only having two such pivot points.
The ediograph is a motion transfer mechanical linkage used to make re-scaled but otherwise identical copies of two dimensional drawings and maps. Users first select the desired ratio of reproduction by adjusting the point of intersection between each side brass arm and the main brass arm by sliding them to the desired measure through the sleeves. Users attach a writing instrument to the brass holder. Users can then trace the original two-dimensional image using the brass stylus and motion will be transferred through the pivot points of the instrument, constrained by the tension of the band and the white string such that the drawing implement will draw the desired re-scaled image on the surface below.
When the instrument is adjusted to perform a one-one mapping of a diagram, the disc supporting the main bar will be perfectly in the middle and each end of the main bar will be fixed perfectly in the middle of the side bars, forming an 'H' shape. Each of the three intersection points can be adjusted in order to adjust the ratio of the mapping.
The ediograph is a motion transfer mechanical linkage used to make re-scaled but otherwise identical copies of two dimensional drawings and maps. Users first select the desired ratio of reproduction by adjusting the point of intersection between each side brass arm and the main brass arm by sliding them to the desired measure through the sleeves. Users attach a writing instrument to the brass holder. Users can then trace the original two-dimensional image using the brass stylus and motion will be transferred through the pivot points of the instrument, constrained by the tension of the band and the white string such that the drawing implement will draw the desired re-scaled image on the surface below.
When the instrument is adjusted to perform a one-one mapping of a diagram, the disc supporting the main bar will be perfectly in the middle and each end of the main bar will be fixed perfectly in the middle of the side bars, forming an 'H' shape. Each of the three intersection points can be adjusted in order to adjust the ratio of the mapping.
ProvenanceDavid Wheatland purchased from William D. Hocker, Inc., Northeast Harbor, Maine, October 25, 1977. Donated to CHSI 1985.
Gebrüder Haff
Date: circa 1949
Accessories: instruction manual for K&E planimeters 4236, 4236M and 4242 in instrument case; instrument case; green cardboard box for instrument case; white card with instrument information inside case
Object number: 2004-1-0346
Gebrüder Haff
Date: circa 1957
Accessories: white card with instrument information inside case
Object number: 1997-1-0447
Gebrüder Haff
Date: circa 1940
Accessories: card with instrument info and conversion table; photocopy of letter from Dr. Joachim Fischer to William J.H. Andrewes, dated 12 May 1997; photocopy of extract from Dr. Joachim Fischer's inventory of integrating instruments included with the letter
Object number: 1997-1-0444
Gebrüder Haff
Date: circa 1940
Accessories: card with instrument information and conversion table
Object number: 1997-1-0445
Gebrüder Haff
Date: circa 1940
Accessories: case
Object number: 1997-1-0446
Gottlieb Coradi
Date: circa 1920
Accessories: pieces of the front of black leather case with clasps; lid of case with paper data sheet; pieces of black leather case lined with green velvet
Object number: 2004-1-0345
Gebrüder Haff
Date: circa 1949
Accessories: instrument case
white card with instrument and measurement information inside instrument case
Object number: 2004-1-0344
Gebrüder Haff
Date: circa 1960
Accessories: black storage case
two white cards with conversion tables inside case
Object number: 1997-1-2000
G. Coradi
Date: circa 1911
Accessories: conversion table on white card in instrument case; instrument case
Object number: 1999-1-0068
Keuffel & Esser Company
Date: 1916-1926
Accessories: wood case and key; photocopy of original Keuffel & Esser Co. catalogue in which the model is introduced
Object number: 1996-1-0084
Adrien Gavard
Date: circa 1860
Accessories: hinged mahogany case with original trade label; extra arm; writing implements; instrument weights; small ivory wheels with brass frames
Object number: 1997-1-1856
Forster
Date: 1950-1960
Accessories: spare ink cartridges; pen attachments
am auxiliary box containing small Allen wrench, scotch tape, extra parts, and storage instructions
Object number: 1999-1-0054