Aug
Bow Wired
Posted in Ribbons | No Comments »how to build an equatorial bow sundial?
I need detailed instructions on bulding an equatorial sundial arc including all formulas and equations. Type a semicircle with markings for hours to cast a line from the shadows. and he has to tell time standard. This clock will be placed in a country near the equator. it will make a difference to the design sundial?
Shadow over the line, the "gnomon" with the axis of the earth. This means that it must point to the North Star, Polaris. If you can not find Polaris, to pointing north, forming an angle with the horizontal is the same as your latitude. The bow must go around the gnomon. A semi-circle is not really enough, as it will only record 6:00 to 6:00 p.m.. Since the summer, when you will get more useful out of it, the sun rises before 6 and sets at 6, you really should bow to spend three-quarters of a full circle around the gnomon, but parts of it will then cast a shadow over other parties. This is probably best to go 8:00 to 8:00 p.m.. Divide 180 degrees of arc in 12 equal segments for 12 hours. Set the arc so the sundial shows from noon to 12 pm Time, rather than local time. This way you will not have to make adjustments. This should be the right under 17 minutes, but you can include a table in the "equation of time" giving minutes to be added or subtracted at times verious of the year.