pantograph
Date: circa 1875
Inventory Number: 5140a
Classification: Pantograph
Subject:
Maker: Keuffel & Esser Company (1867 - 1987)
User: Department of Geology and Geography, Harvard University (1890 - 1961)
Cultural Region:
Place of Origin:
City of Use:
Dimensions:
14.5 × 27.5 × 79.3 cm (5 11/16 × 10 13/16 × 31 1/4 in.)
Accessories: pantograph weight (5140b); wooden stands
DescriptionThe pantograph comes with two rectangular wooden boards, each with a black ebonite strip on the top edge. One of the boards has two grooves cut in the top edge. The other has three. The four arms of the pantograph fit into these grooves such that the boards act as a stand for the instrument. A thinner strip of wood with two brass thumb screws through it fits on the top of each wooden board. When the brass screws are tightened, the wooden strip and board render the pantograph arms immobile.
The Pantograph consists of four brass arms with four pivoting connections. The two longest arms are attached at one end. That end will be referred to as the leftmost extremity of the Pantograph. The two smaller arms are attached at the opposite end. The other end of each smaller arm is attached to one of the longer arms by an adjustable, three-sided brass bracket. The smaller arms are attached with a brass slider and screw. Users can loosen the screw in order to slide the ends of the smaller arms to the desired location. The resulting shape of the Pantograph is a single parallelogram with two extended edges. There is a small steel wheel in a brass frame attached to the bottom of each long arm near their intersection.
A brass pin rises from the intersection of the two long arms. At the opposite end of one of the long arms is a complex brass mechanism. On the very top is a rounded brass dish in which a steel ball weight sits. The weight serves to keep this extremity of the pantograph in contact with the surface below. On the bottom edge of this end of the arm is a cylindrical brass holder for a writing implement. A metal lever with a black ebonite handle emerges from the side of the arm. The rest of the mechanism is constituted by several sliding brass components and round thumb screws, permitting users to adjust the writing mechanism.
At the opposite end of the other long arm is another brass mechanism, this one centered around a steel and brass pin stylus with which users trace figures on the surface below. This end also rests on a third steel wheel in a brass frame. The stylus is accompanied by various brass adjustment thumb screws, and a steel lever with a black ebonite handle.
The Pantograph consists of four brass arms with four pivoting connections. The two longest arms are attached at one end. That end will be referred to as the leftmost extremity of the Pantograph. The two smaller arms are attached at the opposite end. The other end of each smaller arm is attached to one of the longer arms by an adjustable, three-sided brass bracket. The smaller arms are attached with a brass slider and screw. Users can loosen the screw in order to slide the ends of the smaller arms to the desired location. The resulting shape of the Pantograph is a single parallelogram with two extended edges. There is a small steel wheel in a brass frame attached to the bottom of each long arm near their intersection.
A brass pin rises from the intersection of the two long arms. At the opposite end of one of the long arms is a complex brass mechanism. On the very top is a rounded brass dish in which a steel ball weight sits. The weight serves to keep this extremity of the pantograph in contact with the surface below. On the bottom edge of this end of the arm is a cylindrical brass holder for a writing implement. A metal lever with a black ebonite handle emerges from the side of the arm. The rest of the mechanism is constituted by several sliding brass components and round thumb screws, permitting users to adjust the writing mechanism.
At the opposite end of the other long arm is another brass mechanism, this one centered around a steel and brass pin stylus with which users trace figures on the surface below. This end also rests on a third steel wheel in a brass frame. The stylus is accompanied by various brass adjustment thumb screws, and a steel lever with a black ebonite handle.
Signedengraved in script on instrument arm: Keuffel & Esser Co. New York. 4.36
FunctionThe Pantograph is a motion transfer mechanical linkage used to make re-scaled but otherwise identical copies of two dimensional figures (including drawings, letters, and maps). Users first select the desired ratio of reproduction by adjusting the placement of the smaller brass arms on the larger ones and by adjusting the placement of the stylus and writing implement holder. Users then trace the original two-dimensional image with the brass stylus and motion will be transferred through the pivot points of the parallelogram such that the drawing implement will draw the desired re-scaled image on the surface below.
This specific pantograph and weight set was used by the Department of Geology and Geography at Harvard University, likely for cartographic purposes.
This specific pantograph and weight set was used by the Department of Geology and Geography at Harvard University, likely for cartographic purposes.
ProvenanceFrom the Department of Geology, Harvard University, 25 January 1966.
