Hi everyone, I would just like to comment on finding the declination of a wall. I use the method described on page 88-94 of waugh's book except I have the nail driven in from the back so there is a sharp point protruding. I have graph paper taped to the front to help measure horizontally the shadow. Also I have two holes drilled at the top so I can hang the board. You cannot repeatedly get an accurate reading just holding the board against the wall. I am usually accurate to within a degree.
Most walls are not completely flat and you get some movement of the board. If possible I like to mount a blank sundial or board on the wall that I can plumb and know that it is perpendicular to the wall so I know I will not have any distortion when mounting the final dial. I know some people use the horizontal table against the wall method which I feel is not really accurate. I just like to be accurate as possible. Thanks, Ken Clark
