Images(13)

Gurley Y level

Datebefore 1882

Inventory Number5148

ClassificationLevel

Subject

Maker W. & L. E. Gurley 1845 - 1968

Seller Ledder & Probst 1906-1920s

User Harvard Engineering Camp founded 1901

User Department of Engineering Sciences, Harvard University founded circa 1918

Cultural Region

Place of Origin

Place of Use

Dimensionsinstrument: 21.2 × 53.4 × 12.8 cm (8 3/8 × 21 × 5 1/16 in.)
case: 14.4 × 58 × 24.7 cm (5 11/16 × 22 13/16 × 9 3/4 in.)

Material

Accessoriesmahogany case; leather belt; six metal screws; tripod, see 5148

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 foot plate with four leveling screws.

The body of the telescope tube has a black finish which has largely rubbed away; its eyepiece and end cap are in exposed brass. Two brass knobs are bolted to the telescope tube, one near the eyepiece and one between center and the end cap. Around the tube closer to its eyepiece end is a brass ring with brass pegs projecting from it at intervals.The two Y supports are fixed to a level bar with knobby ends and black finish partly rubbed away. The brass pin holding each Y support closed is tied to the neck of the support with a pink and white string.

A spirit level is suspended from two brass posts screwed to the bottom of the telescope tube. It has a glass window in the shape of two ovals connected by a narrow channel. Bolted perpindicular to the window is a thin silver scale with values descending from 30 to 0, then ascending from 0 to 30. The level tube has a black finish.

Directly below the level bar are two knobs projecting from the vertical spindle. One knob is circular with three rings along its edge; the other is shaped like a butterfly.

The exposed-brass footplate is circular, with three rings around its edge. On top of it are four brass leveling screws, each with a circular knob near its center.

The instrument is stored in a mahogany box with two brass clasps. Six short metal screws and a leather belt are also stored in the box.

The instrument's spirit level appears to be empty of liquid. See also the tripod, 5148b.

Signedin script on top of level bar, center: W. & L. E. Gurley / Troy, N.Y.; printed on pink tag attached to instrument: HARVARD ENG. CAMP / ASHLAND N.H.; on label inside box lid: SOLD BY / QUALITY - EFFICIENCY - DURABILITY / [Ledder & Probst trademark] / LEDDER & PROBST INC. BOSTON

Inscribedscratched on bottom of base: B190 ; stamped on box lid, center: Y / LEVEL / 20 ; stamped on box lid, bottom center: PROPERTY OF / HARVARD COLLEGE / 20L pencilled on pink tag attached to instrument: L 59/21 20; in chalk inside box lid, right: 20; in chalk inside box lid, left: No Dust;

Curatorial RemarksThis is level 20 in a series of at least twelve levels once belonging to Harvard's Department of Engineering. (CHSI has levels numbered 2, 3, 6, 7, 8, 12, 14, 19, 20, 21, 22, 24.); See the file for 5148b, which contains a record indicating that in 1882 the instrument was returned from Gurley as "not worth repair".

FunctionFor use in surveying, to measure contours.

After placing the Y level, on a tripod, at his starting location, the user levels the instrument by means of the spirit level and the four 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.

ProvenanceFrom Pierce Hall attic. Received 5/20/61from Harvard Department of Engineering. No Harvard University tag.