A magnetic compass adjuster's bridge pelorus, the case with label inscribed Morton's Patent Altazimuth Compass Corrector with one folding sighting vane, one fixed vane, adjustable hands for setting variation - 10¼in(25.8cm)wide; and three cased and gimballed floating papercard compasses (4)

細節
A magnetic compass adjuster's bridge pelorus, the case with label inscribed Morton's Patent Altazimuth Compass Corrector with one folding sighting vane, one fixed vane, adjustable hands for setting variation - 10¼in(25.8cm)wide; and three cased and gimballed floating papercard compasses (4)