Let me explain how I learned the math. More than twenty years ago I started out with Waugh's book and I could make a vertical declining dial graphically: Draw AB, draw CD perpendicular to AB etc. but I could not calculate one mathematically. Where's the log sin on the calculator? ;-)
I started reading the late Noel C Ta'Bois's monthly article called THE SUNDIAL PAGE in CLOCKS magazine which is published in England. He gave a step by step approach using the scientific calculator. Simply omit "log" wherever it appears and substitute "multiply" or "divide" for "plus" or "minus." He used a step by step approach using formulas and told what keys to press to make a sundial from start to finish. This step by step approach in solving formulas is what I find missing in most sundial instructions. The actual steps and what keys to press and in what order is missing. The understanding will come later. Most new people just want to make a sundial, and they give up when they see the formulas and no instructions on how to solve the formulas. In a hobby that uses so many formulas, what is needed are the instructions to solve the formulae so we all get the same answer. The math can be complicated but if you know the steps to follow, a new person may not be so quick to give up on a great hobby to learn. Ken Clark Elizabethtown, PA
