The oldest scientific instruments - Technology that has stood the test of time (Y2K compliant, naturally)

The sundial was developed by philosophers and does not show the time, but when the shadow moves from one hour line to the next, it means that the world has turned 15 degrees (360 degrees divided by 24 hours). I have sub-divided the hours into 20 minute intervals, which is 5 degrees (4 minutes equals 1 degree). Time can be told from it however, by including the table of corrections, which is composed of the difference in local time to the standard time meridian, which is 30 degrees East, and the equation of time, which is variable.

The angle of gnomon has to be the same as the latitude. The angle is the same as the axis of the world, and looking up, the gnomon will show where the southern celestial pole is.

The numerals run anti-clockwise because we are in the Southern Hemisphere (clocks run clockwise because the sundials in the north run that way).

So when you have your tea or dop in the garden, remember the philosophers of old and think great thoughts.