Inventory no. 33340 - Former Display Label
Irish CIRCUMFERENTOR and MAGNETIC AZIMUTH DIAL 1667
Brass and wood; the combined compass- and dial-card was printed
from an engraved copper plate. The card is signed, "W. R. Dubliñ.
fe. Latitude 53 20 * 1667 *" It is similar to those made, between
1650 and 1660, by Henry Sutton, of London.
If, with the aid of the sights of the circumferentor, the south
point of the compass is directed towards the sun, the compass-needle
will mark the time on the concentric line corresponding to the sun's
declination.
[M. 20]
Other narratives:
- Bennett, J. and Johnston, S., The Geometry of War, 1500-1750 (Oxford, 1996)
- Practical surveying
- Degree scales