- Subject
- Mathematical instruments
- Item type
- Object
- Provenance
- Lent by Christ Church, Oxford in 1925.
- Physical material
- Brass
- Object type
- Alidade
- Dimensions
- Height: 7.5cm Width: 34.7cm Depth: 39.5cm Weight: 1.7kg
- Inventory No
- 18184
- Accession Number
- 1925-43
Description
Separate brass alidade and rule, with detachable sights, associated with John Worgan's plane table.
The alidade has two removable slit and thread sights. One half of the obverse carries a decimally divided 9" diagonal scale; the other has scales of equal parts (10, 16, 20, 24, 32 and 40 to an inch) and two scales of chords. The reverse has a double logarithmic scale of "Numb[ers]", a scale of "Sines" to 90 degrees and a scale of "Tang[ents]" to 45 degrees.
Related Items
More related items
Surveying Alidade, English, c. 1900Inventory Number 22185
Plane-Table Alidade, English, c. 1700?Inventory Number 29239- Plane-Table Alidade with Meridian Trough Compass, English, c. 1800Inventory Number 35095
- Engraved Paper Diagram With Alidade for Sun and Time, English, 18th Century?Inventory Number 18671