Troughton & Simms dumpy level
Dateafter 1900
Inventory Number5219
ClassificationLevel
Subject
Maker
Troughton & Simms
1826 - 1923
Cultural Region
Place of Origin
Dimensions19.5 × 10.7 × 29.5 cm (7 11/16 × 4 3/16 × 11 5/8 in.)
Material
DescriptionBrass dumpy level with the following major components (top to bottom): one large and one small spirit level; telescope tube; and foot plate with four leveling screws.
The large spirit level, which is bolted to the top of the telescope tube, has two oval glass windows. Each window is printed with an unlabeled scale having twelve divisions. Each scale starts some distance in from the window's inner edge.
The small spirit level is mounted crosswise on a U-shaped brass plate extending from one of the large level's mounts. It has a single oval glass window.
The telescope tube has knurling around the eyepiece and the two ends of the larger portion of the tube. Bolted to the side of the telescope tube near the eyepiece end is a singled knurled knob. Near the eyepiece are two brass pins with holes in them, projecting out from the tube opposite one another. Beside one of the pins is a series of slits, each with a circular hole at one end. The objective end of the telescope has a pivoting brass cover. The telescope itself is sandwiched between two brass straps, which in turn are bolted to the level bar.
Below the level bar is a circular brass foot plate with four leveling screws. Each screw has a circular knob with two knurled rings around its edge. The foot plate and the second disc through which the screws project have plain edges. The small disc above the leveling screws has a knurled edge.
The glass window nearest the eyepiece is cracked.
The large spirit level, which is bolted to the top of the telescope tube, has two oval glass windows. Each window is printed with an unlabeled scale having twelve divisions. Each scale starts some distance in from the window's inner edge.
The small spirit level is mounted crosswise on a U-shaped brass plate extending from one of the large level's mounts. It has a single oval glass window.
The telescope tube has knurling around the eyepiece and the two ends of the larger portion of the tube. Bolted to the side of the telescope tube near the eyepiece end is a singled knurled knob. Near the eyepiece are two brass pins with holes in them, projecting out from the tube opposite one another. Beside one of the pins is a series of slits, each with a circular hole at one end. The objective end of the telescope has a pivoting brass cover. The telescope itself is sandwiched between two brass straps, which in turn are bolted to the level bar.
Below the level bar is a circular brass foot plate with four leveling screws. Each screw has a circular knob with two knurled rings around its edge. The foot plate and the second disc through which the screws project have plain edges. The small disc above the leveling screws has a knurled edge.
The glass window nearest the eyepiece is cracked.
Signedengraved on level bar: TROUGHTON & SIMMS / LONDON
Curatorial RemarksThis object was previously numbered DW0378.;
The brass has been sanded, perhaps removing original gunmetal finish.;
See another Troughton & Simms dumpy level, 5208a.
FunctionFor use in surveying, to measure contours.
After mounting the dumpy level on a tripod at his starting location, the user levels the instrument by means of the spirit levels and the 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 dumpy level on a tripod at his starting location, the user levels the instrument by means of the spirit levels and the 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 Roux-Devillas Paris, August 6, 1968 (lot 9/136). Donated to CHSI February 1977.
Keuffel & Esser Company
Date: circa 1909
Accessories: mahogany case with brass corner protectors and lock; key; sunshade; dust cover; tripod (5147b)
Object number: 5147a
Frederick Eckel
Date: circa 1885
Accessories: mahogany case (top very worn); lens hood; sunshade; tripod, see 5151b
Object number: 5151a
Buff & Berger
Date: circa 1880
Accessories: mahogany case; sunshade; screws; dust cover; tripod (5144b)
Object number: 5144a
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
Buff & Berger
Date: circa 1880
Accessories: mahogany case; sunshade; screws; dust cover
Object number: 5143a
P. & R. Wittstock
Date: circa 1900
Accessories: mahogany case; 2 sunshades; dust cover
Object number: 5146a
Buff & Berger
Date: circa 1890
Accessories: mahogany case with lock (key not found); leather strap; screwdriver; dust cover; sunshade; tripod, see 5149b
Object number: 5149a
Troughton & Simms
Date: circa 1840
Accessories: mahogany box with brass hinges and hooks
Object number: 5232
Adie & Son
Date: circa 1850
Accessories: case; dust cap and sunshade; eyepiece
Object number: 5209
Herman E. Fessel
Date: circa 1870
Accessories: mahogany case; sunshade; dust cover; tripod (5145b)
Object number: 5145a
Buff & Buff Manufacturing Company
Date: circa 1938
Accessories: sunshield; mahogany box with brass hinges and hooks; brass butterfly nut
Object number: 1989-1-0025
John H. Temple
Date: circa 1870
Accessories: mahogany case; sunshade; tripod (5142b)
Object number: 5142a
See also/See also
