Main centres: | 1-3 business days |
Regional areas: | 3-4 business days |
Remote areas: | 3-5 business days |
The sextant basically consists of a telescope, a half silvered horizontal mirror which the telescope "looks" through and a moving arm on which the index mirror is fixed. By manipulating this arm a star or other celestial body can be made to appear on the horizon. Accurate adjustments are made by means of a micrometer knob. The angle can then be read off the arc and micrometer. The shades are to use when the object being looked at is bright - such as the sun.
The trick is to make the celestial body just brush the horizon - and herein lies somewhat of a knack.