surveying "Y" Level
Datecirca 1850
Inventory Number5221
ClassificationSurveyor's Level
Subject
Maker
W. & S. Jones
fl. 1791 - 1859
Cultural Region
Place of Origin
Dimensionslevel: 12 × 31.2 × 5.5 cm (4 3/4 × 12 5/16 × 2 3/16 in.)
case: 6.5 × 34.3 × 14.4 cm (2 9/16 × 13 1/2 × 5 11/16 in.)
case: 6.5 × 34.3 × 14.4 cm (2 9/16 × 13 1/2 × 5 11/16 in.)
Material
Accessoriespainted wood box
DescriptionBrass Y level consisting of the following major components (from top to bottom): a telescope tube in two Y supports; a spirit level; and a tripod mount socket.
The body of the telescope has a black finish; its knurled eyepiece and end cap are in exposed brass, as are the portions of the tube under the Y supports. One knurled brass knob is bolted to the top of the center of the tube. The two Y supports are fixed to a level bar finished in black. The Y supports are each held closed by a brass pin with a brass loop at its opposite end. A black string tied through each pin's loop is threaded through the neck of the same support. A knurled knob projects out from either end of the level bar, one horizontally and the other vertically. A flat brass tab extends down from the end of the bar with the horizontal knob.
Suspended from the telescope tube on two brass pins is a brass spirit level, finished in black. It has a single oval window, through which the liquid inside is visible. Printed on this window on either side of a central gap are two unlabeled scales, each with ten divisions.
Projecting down from the level bar, which is finished in black, is a socket for mounting the level on a staff, also with a black finish. There is a single knurled knob in exposed brass on the side of the staff mount.
The instrument is stored in a leather box, painted brown, with two brass clasps.
The body of the telescope has a black finish; its knurled eyepiece and end cap are in exposed brass, as are the portions of the tube under the Y supports. One knurled brass knob is bolted to the top of the center of the tube. The two Y supports are fixed to a level bar finished in black. The Y supports are each held closed by a brass pin with a brass loop at its opposite end. A black string tied through each pin's loop is threaded through the neck of the same support. A knurled knob projects out from either end of the level bar, one horizontally and the other vertically. A flat brass tab extends down from the end of the bar with the horizontal knob.
Suspended from the telescope tube on two brass pins is a brass spirit level, finished in black. It has a single oval window, through which the liquid inside is visible. Printed on this window on either side of a central gap are two unlabeled scales, each with ten divisions.
Projecting down from the level bar, which is finished in black, is a socket for mounting the level on a staff, also with a black finish. There is a single knurled knob in exposed brass on the side of the staff mount.
The instrument is stored in a leather box, painted brown, with two brass clasps.
Signedengraved on top of level bar: W & S. JONES. 30 Holborn LONDON
Curatorial RemarksCan delete images B51053 and B51054; these are identical to, though lighter than, images B501468, B501469.;
This object was previously numbered DW0483.
FunctionFor use in surveying, to measure contours.
After mounting the Y level on a tripod at his starting location, the user levels the instrument by means of the spirit level and the knobs on the level bar. 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 Y level on a tripod at his starting location, the user levels the instrument by means of the spirit level and the knobs on the level bar. 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 Saul Moskowitz, Marblehead, Massachusetts, May 7, 1974. Donated to CHSI February 1977.
Frederick Eckel
Date: circa 1885
Accessories: mahogany case (top very worn); lens hood; sunshade; tripod, see 5151b
Object number: 5151a
Buff & Buff Manufacturing Company
Date: circa 1938
Accessories: sunshield; mahogany box with brass hinges and hooks; brass butterfly nut
Object number: 1989-1-0025
Troughton & Simms
Date: circa 1840
Accessories: mahogany box with brass handle; sun shade for telescope
Object number: 5234
C. L. Berger & Sons
Date: circa 1902
Accessories: pine case with lock (key not found); screwdriver; leather strap; sunshade; dust cover; tripod (see 5161b)
Object number: 5161a
R. Iseli
Date: circa 1880
Accessories: walnut case with two adjustment tools, objective lens cap, and lens shade; Iseli trade card (inside box lid)
Object number: 5229
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
Edward Nairne
Date: circa 1790
Accessories: mahogany box with clasp closure
Object number: 5228
Buff & Berger
Date: circa 1880
Accessories: mahogany case; sunshade; screws; dust cover
Object number: 5143a
Buff & Berger
Date: circa 1880
Accessories: mahogany case; sunshade; screws; dust cover; tripod (5144b)
Object number: 5144a
John H. Temple
Date: circa 1870
Accessories: mahogany case; sunshade; tripod (5142b)
Object number: 5142a
Keuffel & Esser Company
Date: circa 1909
Accessories: mahogany case with brass corner protectors and lock; key; sunshade; dust cover; tripod (5147b)
Object number: 5147a
See also/See also
