overall: 2.3 cm x 12 cm x 11 cm; 29/32 in x 4 23/32 in x 4 11/32 in
Object Name:
reflecting horizon
Description:
Navigators using a sextant might use an artificial horizon when the natural horizon is not easily seen. Artificial horizons employing a flat piece of black glass came into use in England in the early nineteenth century. This example is unsigned.
Ref: William Pearson, An Introduction to Practical Astronomy (London, 1829), p. 295 and pl. XXIX.