surveyor's level
Datecirca 1830
Inventory Number5214
ClassificationLevel
Subject
Maker
Etienne Lenoir
1744 - 1832
Cultural Region
Place of Origin
Dimensionslevel: 13.1 × 7.5 × 27.7 cm (5 3/16 × 2 15/16 × 10 7/8 in.)
case: 8.5 × 31.5 × 15.8 cm (3 3/8 × 12 3/8 × 6 1/4 in.)
case: 8.5 × 31.5 × 15.8 cm (3 3/8 × 12 3/8 × 6 1/4 in.)
Material
AccessoriesT-shaped mahogany case; knob for socket mount
DescriptionBrass surveyor's level with the following major components (top to bottom): telescope tube; spirit level; level bar with two leveling screws; and socket mount.
The telescope tube and spirit level are mounted side by side on blocks on top of the leveling bar, and are secured in place by a brass strap with a horizontal knob having two knurled rings around its edge for tightening. Both tubes may be rotated 180 degrees independently.
Both the eyepiece and objective ends of the telescope tube are knurled. Around the telescope tube near the eyepiece is a brass ring with a single brass pin projecting up from it. A second brass ring near the objective end of the tube has multiple projections. Two rectangular brass rings protect the telescope tube from its support
The spirit level has a single oval glass window divided into three parts by two thin brass bands.
Below the level bar is a brass crosspiece, from which is projected a single horizontal knob with two knurled bands around its edge. Two vertical leveling screws with knobs (also having two knurled bands around their edges) at their bottom ends extend through the crosspiece to touch the level bar above.
At the bottom of the level is a cylindrical socket mount with a circular hole near its bottom edge, for a knob with two knurled rings around its edge (in case).
The instrument is stored in a T-shaped mahogany case with brass hinges and hooks.
The telescope tube and spirit level are mounted side by side on blocks on top of the leveling bar, and are secured in place by a brass strap with a horizontal knob having two knurled rings around its edge for tightening. Both tubes may be rotated 180 degrees independently.
Both the eyepiece and objective ends of the telescope tube are knurled. Around the telescope tube near the eyepiece is a brass ring with a single brass pin projecting up from it. A second brass ring near the objective end of the tube has multiple projections. Two rectangular brass rings protect the telescope tube from its support
The spirit level has a single oval glass window divided into three parts by two thin brass bands.
Below the level bar is a brass crosspiece, from which is projected a single horizontal knob with two knurled bands around its edge. Two vertical leveling screws with knobs (also having two knurled bands around their edges) at their bottom ends extend through the crosspiece to touch the level bar above.
At the bottom of the level is a cylindrical socket mount with a circular hole near its bottom edge, for a knob with two knurled rings around its edge (in case).
The instrument is stored in a T-shaped mahogany case with brass hinges and hooks.
Signedprinted on trade card inside box lid: Lenoir / Ingénieur du Roi pur les Instruments / á l'usage des Sciences / Rue Saint Honoré, No. 340, près de la place Vendôme.
Curatorial RemarksThis object was previously numbered DW0694.;
Images B501061, B501062, B501063 may be removed. These are duplicated (in better exposure) as B501476, B501477, B501478.;
As with a Y level, the telescope can be reversed for leveling purposes. The telescope's supports, however, are not the usual Y shape.
FunctionFor use in surveying, to measure contours.
After mounting the instrument on a tripod at his starting location, the user levels the instrument by means of the spirit level and leveling screws. Then he sights a stadia rod through the telescope, moving the rod as needed until the target is centered behind the telescope's cross hairs. The difference in height between the telescope and the rod target indicates the gain in elevation over the horizontal distance between the two.
After mounting the instrument on a tripod at his starting location, the user levels the instrument by means of the spirit level and leveling screws. Then he sights a stadia rod through the telescope, moving the rod as needed until the target is centered behind the telescope's cross hairs. The difference in height between the telescope and the rod target indicates the gain in elevation over the horizontal distance between the two.
ProvenanceDavid Wheatland purchased from Timothy Trace, Peekskill, New York, May 20, 1960. Donated to CHSI February 1977.
Buff & Berger
Date: circa 1880
Accessories: mahogany case; sunshade; screws; dust cover
Object number: 5143a
Troughton & Simms
Date: circa 1840
Accessories: mahogany box with brass handle; sun shade for telescope
Object number: 5234
Date: circa 1850
Accessories: pine case with brass hinges, hooks, and locks; small mahogany (?) box for spirit level; brass sun shade
Object number: 5222
Johann Christoph Voigtländer
Date: circa 1754
Accessories: wooden display stand
Object number: DW0806
Keuffel & Esser Company
Date: circa 1909
Accessories: mahogany case with brass corner protectors and lock; key; sunshade; dust cover; tripod (5147b)
Object number: 5147a
James E. Moody
Date: circa 1880
Accessories: mahogany case; sunshade; dust cap; tripod (5141b)
Object number: 5141a
Spencer, Browning & Rust
Date: circa 1800
Accessories: mahogany case with brass hooks and hinges; lens cap
Object number: 5137
Troughton & Simms
Date: circa 1840
Accessories: mahogany box with brass hinges and hooks
Object number: 5232
Iszard-Warren Co., Inc.
Date: circa 1910
Accessories: mahogany case with brass corners and lock; key missing; leather strap; screwdriver; dust cover; sunshade; tripod, see 5150b
Object number: 5150a
Herman E. Fessel
Date: circa 1870
Accessories: mahogany case; sunshade; dust cover; tripod (5145b)
Object number: 5145a
See also/See also
