plate measuring engine
Date1870-1890
Inventory Number1996-1-0248
ClassificationMeasuring engine
Subject
Maker
A. Repsold & Söhne
1867 - 1919
User
Oak Ridge Station
1931 - 2005
User
George R. Agassiz Station, Harvard
1951 - 1982
User
Harvard College Observatory
founded 1839
Cultural Region
Place of Origin
Dimensions34 x 47 x 52 cm (13 3/8 x 18 1/2 x 20 1/2 in.)
Material
DescriptionThis instrument is mounted atop three tapered cylindrical legs. The legs, which are a deep green color, attach at the top to the outside of a circle of the same color. Atop this circle, which has a large circular hole in it, are two distinct components.
The first has as its base and axis a cylinder straddling (off-center) across the hole. This cylinder is mounted on the rim of the main circle with a thick brass vertically-oriented semi-circle. Movably affixed along this axis is a smaller green circle, under which there are at least three flat brass discs that can be turned for fine adjustment.
The second component is a large I-bar that is mounted in an upside-down U-shape on an axis perpendicular to that of the above described component. Along the top, on one side, are affixed four identical black cylinders with brass caps covering their tops and bottoms. On the other side is the largest brass adjustment knob which can move one of the two middle cylinders.
At the 'back' of the circular base is a pulley. A short string is attached to the base of the higher circle and is run through the pulley.
The first has as its base and axis a cylinder straddling (off-center) across the hole. This cylinder is mounted on the rim of the main circle with a thick brass vertically-oriented semi-circle. Movably affixed along this axis is a smaller green circle, under which there are at least three flat brass discs that can be turned for fine adjustment.
The second component is a large I-bar that is mounted in an upside-down U-shape on an axis perpendicular to that of the above described component. Along the top, on one side, are affixed four identical black cylinders with brass caps covering their tops and bottoms. On the other side is the largest brass adjustment knob which can move one of the two middle cylinders.
At the 'back' of the circular base is a pulley. A short string is attached to the base of the higher circle and is run through the pulley.
Signedembossed and framed: A. REPSOLD / & SÖHNE / HAMBURG.
FunctionInstrument for measuring and examining stars on photographic plates taken with an astrograph (i.e., a photographic telescope).
ProvenanceHarvard College Observatory, Agassiz Station, transferred to CHSI.
Historical AttributesUsed by Harvard College Observatory and transferred to CHSI from its Agassiz Station.
W. Watson & Sons Ltd.
Date: circa 1885
Accessories: oculars (2 pairs): B and D; objectives in marked canisters (4): 1/4, 1/2, 1, 3 inches; condenser with iris diaphragm; rotating wheel diaphragm; iris diaphragm; set of 4 disk diaphragms in brass box; triple nosepiece; live box; prisms for Wenham binocular system (2); stage for simple microscope with rotating wheel diaphragm; vulcanite stage; spare knobs (2); parts box; case
Object number: 1249
Alvan Clark and Sons
Date: 1910
Object number: 2003-1-0077b
Walter Balcke
Date: 1955
Accessories: mahogany box with plexiglass lid; pencil; eraser; box of lead; putty ball; cleaning cloth; cardboard instruction card
Object number: 1997-1-1619
E. Ducretet & Cie
Date: circa 1879
Accessories: None
Object number: 1999-1-0018
Société Genevoise pour la Construction d'Instruments de Physique et de Mécanique
Date: 1895-1905
Object number: HA0111
