measuring engine
Date1940s-1950s
Inventory Number2005-1-0017
ClassificationMeasuring engine
Subject
Maker
Mann Instrument Company
1920 - 1959
User
Harvard College Observatory
founded 1839
Cultural Region
Place of Origin
Place of Use
Dimensions50 x 79 x 79 cm (19 11/16 x 31 1/8 x 31 1/8 in.)
Material
DescriptionMeasuring engine with a bed that moves in two dimensions and a magnifying viewer.
The bed is a hollow three-dimensional trapezoid made of black-enameled metal with an open top and four feet. At the right end of the bed is a brass wheel with a scale around the edge. Attached to that wheel coaxially is a second wheel, black with rounded edges, with a handle on the edge that is parallel to the axis of the wheels. A platform, whose length is perpendicular to the length of the bed, slides along the bed. A ruler on the front top edge of the bed allows the user to mark the exact position of the platform along the bed.
At the front end of the platform is another wheel, this one with a ridged edge, with a scale on it. Attached to the edge of the platform, right by the wheel, is a rectangular metal slab that hangs down from the edge. The slab has a hole in the shape of a square with a semicircle on one side. Around the hole are four horizontal slats.
On one side of the length of the platform is a ruler, along which another platform, square with a circular hole, slides. around this hole is a toothed wheel, on top of which is a metal circle with a square cut out of it. At each corner of the square is a clip with a screw attaching it to the metal circle. Along the side of the wheel are two verniers and a small toothed wheel interlocking with the larger wheel. That wheel is turned with a screw.
Hanging over the platform is an arm, attached to the rear of the bed, containing a microscope looking straight down to the plateholder. The arm tapers as it reachs the eyepiece assembly in front.
The bed is a hollow three-dimensional trapezoid made of black-enameled metal with an open top and four feet. At the right end of the bed is a brass wheel with a scale around the edge. Attached to that wheel coaxially is a second wheel, black with rounded edges, with a handle on the edge that is parallel to the axis of the wheels. A platform, whose length is perpendicular to the length of the bed, slides along the bed. A ruler on the front top edge of the bed allows the user to mark the exact position of the platform along the bed.
At the front end of the platform is another wheel, this one with a ridged edge, with a scale on it. Attached to the edge of the platform, right by the wheel, is a rectangular metal slab that hangs down from the edge. The slab has a hole in the shape of a square with a semicircle on one side. Around the hole are four horizontal slats.
On one side of the length of the platform is a ruler, along which another platform, square with a circular hole, slides. around this hole is a toothed wheel, on top of which is a metal circle with a square cut out of it. At each corner of the square is a clip with a screw attaching it to the metal circle. Along the side of the wheel are two verniers and a small toothed wheel interlocking with the larger wheel. That wheel is turned with a screw.
Hanging over the platform is an arm, attached to the rear of the bed, containing a microscope looking straight down to the plateholder. The arm tapers as it reachs the eyepiece assembly in front.
Inscribedstamped label: US Government Property -- 91760-090002
painted: 10005
FunctionMeasuring engines are used for detailed measurements of features on photographic plates. One of its frequent uses (such as this particular one) is in astronomy to register the positions of stars.
They are also used in aerial photograpy, and in spectrography.
They are also used in aerial photograpy, and in spectrography.
ProvenanceHarvard College Observatory.
Benjamin Martin
Date: circa 1766
Accessories: rope cord belt
glass globe
conducting pad
in folder: photographs, page containing description, history, and discussion of design, note from Ebenezer Gay regarding conservation work, excerpt from David Pingree Wheatland and I. Bernard Cohen, A Catalogue of Some Early Scientific Instruments at Harvard University (Cambridge, MA: Harvard University, 1949), woodcut with picture of instrument from B. Martin, Young Gentleman and Lady's Philosophy (1759): 139.
X-ray images of parts of the machine can be found in C1-A7.
Object number: 0013
French
Date: circa 1880
Accessories: protecting case with glass window
Object number: DW0095
Hammond Typewriter Company
Date: circa 1923
Accessories: four Hammond type shuttles for different type faces, each with a wooden storage box; four laminated paper rectangles with symbol placement guide; instruction book, instruction sheets, advertisements, and correspondence (in object file)
Object number: 1996-1-0373
Carl Zeiss Jena
Date: circa 1926
Accessories: wooden box with two hook-and-eye latches to fasten front opening; in instrument file: instruction book (photocopy); Geissler tube labeled "H2"; carboard tube containing German thermometer C in stainless steel holder that screws into instrument; glass bottle with cork stopper labeled "Monobromnaphthalin, Germany nD=1 658"; small round cardboard box labeled "For Pulfrich Refractometer" containing one tubulure
Object number: 1996-1-0229
Harvard College Observatory
Date: circa 1869
Object number: 1996-1-0082
E. Hartnack & A. Prazmowski
Date: circa 1870
Accessories: objectives (7): 1, 2, 4, 5, 7, 9,10 in fitted box ; eyepieces (4): 1, 4, 5, 6; cup diaphragms (4); polarizer set; bull's eye condenser on stand; Oberhaeuser-style camera lucida; tweezers; substage rotating wheel diaphragm attached to holder with blue glass filter; substage glass filter holder with blue glass filter; substage condenser; dual nosepiece, Hartnack 1/100 mm stage micrometer; flat case; key; magnification table; price lists (2).
Object number: 1080
Jakob Amsler
Date: circa 1906
Accessories: instrument is in four (4) parts; the rail is in own box and is inventory # 2006-1-0002b; letter from Prof. William Brower containing the complete history of ownership and use (missing)
Object number: 2006-1-0002a
Reynolds Metal Company
Date: circa 1944
Accessories: see Description for itemized list
Object number: 1997-1-0796a
Reynolds Metal Company
Date: circa 1944
Accessories: see Description for itemized list
Object number: 1997-1-0796b
Reynolds Metal Company
Date: circa 1944
Accessories: see Description for itemized list
Object number: 1997-1-0796c
