dip needle
Date1850-1900
Inventory Number0113
ClassificationDip Needle
Subject
Maker
American
?
User
Department of Physics, Harvard University
founded 1884
Cultural Region
Dimensions13.1 × 22 × 9.3 cm (5 3/16 × 8 11/16 × 3 11/16 in.)
Material
DescriptionThis dip needle consists of semicircular altitude scale mounted on a circular brass base with an upright pivot point in the center. The needle is missing, as is the horizontal divided circular scale that once was soldered to the altitude scale near the 60° marks. (Half of the horizontal scale is visible in the photograph on the old inventory card.)
The altitude scale is crudely divided 0°-90°-0° every 5°. The numerals are stamped. The horizontal scale (missing) is divided 0°-90°-0°-90°-0° every 5°.
The circular base was cast from an alloy rich in copper. It was then turned and trimmed with knurling.
The altitude scale is crudely divided 0°-90°-0° every 5°. The numerals are stamped. The horizontal scale (missing) is divided 0°-90°-0°-90°-0° every 5°.
The circular base was cast from an alloy rich in copper. It was then turned and trimmed with knurling.
Signedunsigned
Curatorial RemarksThis instrument is later than those produced by the Boston maker, Daniel Davis, Jr., but as in his examples, the needle is free to orient in any direction.
FunctionThis form of dip needle would have been used to show the orientation of a magnetic field in the horizontal and vertical planes. The user could work with the earth's magnetic field or a field generated by a lodestone or electromagnet.
This particular instrument is too crudely engraved to have been intended for geomagnetic research on the dip and variation of the earth's magnetic field.
From Instrument Card:
Brass semicircle with 0-90-0. Circular brass base with vertical support for needle (needle missing). Circular scale horizontally attached to base of semicircle (half missing).
This particular instrument is too crudely engraved to have been intended for geomagnetic research on the dip and variation of the earth's magnetic field.
From Instrument Card:
Brass semicircle with 0-90-0. Circular brass base with vertical support for needle (needle missing). Circular scale horizontally attached to base of semicircle (half missing).
ProvenanceDepartment of Physics, Harvard University; transferred to CHSI, 1956.
Barthélémy Urbain Bianchi
Date: ca. 1840
Accessories: housed in pine box
Object number: 5212
Edward Nairne
Date: 1765
Accessories: Small magnifying glass on end of box to assist in aligning the dip needle.
Object number: 0026
W. & L. E. Gurley
Date: ca. 1884
Accessories: solar attachment; case; level; green filter; sun shade; tripod (5163b)
Object number: 5163a
Antonius Giamin
Date: early 20th Century
Object number: DW0590
W. & L. E. Gurley
Date: 1950
Accessories: leather carrying pouch
Object number: 1996-1-0638
Kelvin Bottomley & Baird Ltd.
Date: circa 1910
Accessories: mahogany case
HUSUN catalogue (in instrument file)
Object number: 5335c
