Berger & Sons geodetic level
Date: circa 1902
Inventory Number: 5161a
Classification: Surveyor's Level
Dimensions:level: 32 × 15 × 41 cm (12 5/8 × 5 7/8 × 16 1/8 in.)
case: 26.4 × 46.6 × 26.3 cm (10 3/8 × 18 3/8 × 10 3/8 in.)
Accessories: pine case with lock (key not found); screwdriver; leather strap; sunshade; dust cover; tripod (see 5161b)
DescriptionGeodetic level with textured finish consisting of the following major components (from top to bottom): spirit level; telescope tube in Y supports; level bar with micrometer adjustment; three leveling screws.
The spirit level, which has a single oval glass window, is suspended above the telescope tube on two vertical arms projecting up from either side of the telescope tube's cradle. A metal pin with a loop at one end anchors the spirit level to these arms. A string through the pin's loop is tied around the point of attachment between the telescope tube's cradle and the level bar. The caps at either end of the spirit level tube are shaped like inverted U's, and rest on top of the telescope tube. The spirit level scale is marked with two dots, one at the middle of each side, and graduated in single units, with the 5's marked to the right and left of each red dot.
Mounted on the level is a rectangular metal (aluminum?) bar hinged at the middle from a metal structure, topped with a wooden knob.
Two steel rings clamped around the telescope tube protect its points of contact with the Y supports. Both ends of the telescope tube are unfinished. Around each is a white celluloid ring with knurling. Projecting out from the tube between the steel ring and the celluloid ring near the eyepiece end is a white celluloid knob with knurling. Just inside the knurled eyepiece, four metal pins project out from the telescope tube.
Each Y support is held closed by a metal pin with a loop at one end. A string through each loop ties it to the respective end of the telescope tube's cradle.
The telescope tube's cradle and the level bar are pinned together at the vertical spindle by a large steel bolt. Projecting up through each end of the level bar and resting on the bottom of the cradle is a small metal pin. One pin has a knurled knob at its end.
Projecting up through the opposite end of the level bar is a leveling screw with a knurled knob. Between the knob and the level bar is a white celluloid drum printed with a single scale with two sets of values. One set of values descends from 100 to 0; the second set ascends from 0 to 100. Resting against the side of the drum is a thin steel sheet engraved with a micrometer scale.
Three leveling screws projecting down from a metal piece shaped like a three-pointed star. Each screw has a knurled knob at its center. An additional knurled knob projects out horizontally from the foot plate near two of the leveling screws. Above the star-shaped piece are two more knurled knobs, one projecting out directly from the vertical spindle, and one projecting out from one of the two horizontal metal bars held against the vertical spindle.
Below the leveling screws is a threaded post for mounting.
The level is stored in a pine case with a leather strap. Also in the case are a sunshade and a dust cover.
See also the tripod for this level, 5151b.
Signedblue label affixed to inside of lid: C.L. BERGER & SONS / Manufacture all kinds of / Surveying, Engineering, Astronomical & Instruments,
No.9 Province Court, Boston, Mass. / [instructions of use follow];
Inscribedengraved on box lid: PRESISSE / [LETTER CROSSED OUT] LEVEL / 12 / L.S.S.12L / L.S.S.12L;
metal plaque on box lid: HARVARD UNIVERSITY / 1730;
on inside of lid, and back wall of box: several white labels with instructions for use;
orange tag: DIVISION OF ENGINEERING, / HARVARD UNIVERSITY, / PIERCE HALL, / CAMBRIDGE, MASS. / (back of tag) L12 / B / Precise Level;
white paper label pasted in front side of box: SPECIAL ! / IN CASE OF REPAIR BEING NECESSARY, REMEMBER / the maerks of this instrument will pay expressage one way, and since they have all the tools, sizes and parts on hand, can save you considerable and do a far better repair than anyone else / MARK BOX / BUFF & BUFF MFG CO., / Jamaica Plain Station, BOSTON, Mass. / and order us to make "complete repairs", when your instrument will be given early attention and returned ...[label cut to fit lid support]
FunctionFor use in geodetic surveying, to determine differences in height between points, as well as with respect to references (such as mean sea level).