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artificial horizon Used to take celestial sextant sights when no ocean or shoreline is available. It can be a plate of water, oil, or molasses or a mirror. The surface must be protected from the wind as the slightest breeze will distort the surface. It takes a mirror to do star sights. See note on molasses example. The sextant angle measured with an artificial horizon is twice what the angle is, so we are limited to heights below about 60º for most sextants (which span 120º on the arc). Note that the sextant telescope must allow for focusing at this close distance 3 to 10 ft. Some stock 4x40 Tamaya scopes will not allow for that. The Astra scopes work fine. If water is nearby, you can usually get more realistic sextant practice using a shoreline. See Dip short.

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