细节
THE COMPASS USED ON THE TRANS-AFRICAN EXPEDITION
A BRASS-CASED SIGHTING COMPASS
the floating dial signed H. HUGHES & SON, 59. FENCHURCH ST, LONDON, with graduations in degrees and compass directions printed in mirror image, with two folding sights, one with a 45° mirror to read the compass scale and two folding shades, the other with a sliding and folding mirror attachment - 100mm. diameter