Surveying Instrument Collection
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Maker |
Fennel Kassel (Germany) |
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Model |
N/A |
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Serial Number |
62179 |
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Dimensions |
Length 200mm, Width 130mm, Height 180mm |
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Image |
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Description |
This instrument (also known as a "Magnet Theodolite") is used for the determination of magnetic declination. The instrument features two plate bubbles in opposite directions and an altitude bubble. A black rectangular box houses a magnetic needle with a scale of +20 to -20 graduations and this system is known as the 'Duplex Magnet System'. Each one of these graduations represents a horizontal angle of one minute (1'), and is used to evaluate the deviation of the collimation line from the upper half of the graticule, after the reflection from the plane mirror attached to the Duplex Magnet System. The instrument also incorporates an auto-collimating telescope with the illuminating prism pushed into the "down" position. Furthermore, a mirror is used to collect the light to provide the best illumination possible into the field.
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History & comments |
There is no historical information available. |
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Conservation |
In a fine box |
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Condition |
Excellent |
| Remarks |
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Dates |
Manufactured in 1960 (approx). Catalogued in 1997 |
