- Building sundials-
The watch dial vertical is more complex in design than dial equator, because the divisions indicating the time does not correspond to the simple division angle equal parts of 15 degrees of tilt per hour, but a graduated scale distorted by the vertical projection of the quadrant equator. However, for this instrument is functional, the gnomon must be parallel to the axis of the world, pointing to the poles in the same manner as the sundial equatorial dial.
With our knowledge of geometry and trigonometry in high school we acquired the ability to design and projecting a dial sundial vertical, horizontal and declining among others, once assimilated the idea of \u200b\u200bthe equatorial quadrant projections on other surfaces.
The following image shows the mathematical development to determine the projection of the equatorial quadrant hour angles on the vertical quadrant.
As in the case of dial sundial equatorial foot on this clock also serves both functions, support and gnomon. The following figures show some of the steps for making clock model.
Templates.
Templates cut and pasted to the cardboard base.
Cutting binding groove of the foot to support gnomon.
union slots completed.
Quadrant front or north side.
Quadrant
rear or southern side.
Front View.
Side view.
Note in side view the sundial is completely vertical, but the upper surface of the foot, which is the gnomon is tilted. The angle of inclination with respect to the horizontal have the same value as the latitude.
To view the local solar time, we must put our clock in a sunny spot and oriented in the same way as previous clocks, ie, the gnomon must point to the poles and parallel to them.
0 comments:
Post a Comment