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Locomotion
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Locomotion
National Railway Museum
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Image
Has Image
5
Non-Commercial Use
5
Category
Surveying
5
Maker
E. R. Watts & Son
1
Hilger & Watts Ltd
1
Hilger and Watts Limited
1
J H Steward
1
J. H. Steward
1
Object type
optical square
5
plummet level
1
Place
Debden
1
Europe
1
London
1
Strand
1
United Kingdom
1
Material
brass (copper, zinc alloy)
4
glass
4
steel (metal)
3
cardboard
2
felt
1
leather
1
leatherette
1
metal (unknown)
1
paint
1
plastic (unidentified)
1
Date
From year
To year
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'Sitesquare' optical square, British, 1959
1959
Optical square, British, 1851-1917
1851-1917
'pop-eye' optical square, British, 1980-1985
1980-1985
Optical square for use with telemeter, British, 1904-1911
1904-1911
Combined optical square & hand level, British, 1920-1926
1920-1926
