MY HOME SUNDIALS
This vertical declining sundial on the wall of our house in Shropshire, England faces 18 degrees East of South. It is 450 mm. wide and 600 mm. tall made up of 12 separate tube-lined ceramic tiles, each 150 mm. square.I did the calculations and the design. The tiles were made at the Jackfield Tile Museum by "The Decorative Tile Works".
The dial is designed to show British Summer Time, (one hour ahead of Greenwich Mean Time). In addition to the conventional hourlines, the dial has three 'lines of declination'. Partway along the gnomon, clearly visible on the photograph, is a small ball, called a 'nodus'. The lines of declination are plotted in such a way that, throughout a particular day of the year, the shadow of the nodus tracks along the length of the line, starting at the left hand end in the morning and ending at the right hand end in the evening.
The upper line of declination on my dial is for 14th February, my wife's birthday. the lower one is for June 24th, my birthday, and the one in the middle is for August 30th, our wedding anniversary. The photograph was taken on my wife's birthday, at about 11.25 a.m. British Summer Time, (10.25 a.m. GMT)
MY PORTABLE HORIZONTAL BIFILAR DIAL
I constructed this portable dial, approximately 150mm square, using Valentin Hristov' Deltacad Macro "Bifilar Dial".
I used the piece of white cardboard, with the hour and month curves, computer-printed on photo paper and glued to it.
The transparent "pillars" hold the two black elastic threads, one running from North to South, the other from West to East.
To aid the correct N-S alignment of the dial, I added a small magnetic compass. (In Central England, the magnetic deviation at present is only 4 degrees.)
Where the shadows of the threads cross shows the dial's time and the date, in this case, 9.55 a.m. GMT on 2 February..
MY MILLENIUM HORIZONTAL SUNDIAL
For the millenium, I designed this circular horizontal dial for our garden in Newport, Shropshire, England ( 52degrees 46minutes North and 2degrees 22minutes West).
I used the Postscript computer language to design the dial. The dial is chemically etched in brass with hourlines from 6 a.m.to 6 p.m. On the chapter ring, there are minute divisions.
The dial shows local time but at the top of the dialplate there is a graph showing the difference from civil time, taking account of EOT and longitude.