Year 2005
Work of our members
Saw your sundial, Sir?
Do as Henric Bierum shows on the frontispiece of his 1676 book:Saw your own sundial for any desired plane.
This shows how to construct a sundial. The examples below implement this idea in as didactically valuable a manner as possible.
A small block of wood, parallel to the axis of the earth, sits on a pergola.
Both crosscuts are marked with a wheel with 24 spokes: the hours, with XII hours in the lower middle. (hardly visible in the photograph)
The spokes extend to the sides, and parallel lines on the sides connect pairs of corresponding, upper and lower, spokes.
If we saw through the block and draw spokes on the new cut faces, connecting pairs of corresponding side lines, we will have constructed a pair of correct sundials.
The above example shows the saw cuts for a horizontal sundial, and below is an example of how even the remains can make a functional sundial.
By its corpulence, the sundial shows how it was made.
The brass triangle shows details on the sundial and the equation of time.