Description of the Fog-signalling Apparatus by aerial and submarine waves used on board the Light-ship Fladen PDF
L. Tonta Concerning the correction of the quadrantal error in compasses of large magnetic moments PDF
J. Luymes War Er Gebeurt Ter Bevardering Van Het Gebruik Van Oorspronkelijke Zeekaarten: (What has been accomplished in developping the use of original charts) PDF