Mr. Sharp, of Dublin, exhibited to the British Association in 1849 a
Dial, consisting of a cylinder set to the day of the month, and then
elevated to the latitude. A thin plane of metal, in the direction of
its axis, is then turned by a milled head below it till the shadow is
a minimum, when a dial on the top shows the hours by one hand, and the
minutes by another, to the precision of about three minutes.