151
The German Hydrographic Institute in the year 1967
the department Nautical Engineering- of the DHI. to conduct magnetic measure
ments during the different stages so that the influence, of the individual
components on the magnetic field at the compas.s place could be ascertained.
International co-operation in the field of magnetic compasses resulted in
the completion of test regulations for magnetic compasses, binnacles, and
correcting devices. Sondes for measuring the velocity of sound in sea water
were fitted with a new casing enabling them to measure also at depths of
6,000 in. In the establishment of the Frisian Decca chain this department
had an advisory function.
In the department Geophysics and Astronomy the- knowledge of the-time
difference by which the wind effect on the 'water lags behind the wind could
be improved by adjusting the wind effect at Cuxhaven by means of a Fourier
series. A comparison of sea clutter on radar photographs with stereophoto-
grammetric pictures of the sea seems to prove the assumption that single
returns are. extinguished by interference. In order to accelerate the dis
semination of information about geomagnetic variations, microfilms of the
recordings were produced for the first time arid dispatched to the World
Data Center A.
In the department Oceanography current and radioactivity measurements
had preference in the work at sea. The measurements of waves were continued
at 1? stations off the home coasts. The installation of an automatically
operating- station of measurement, in the Kiel lighthouse is a first step,
towards the creation of a network of oceanographic stations for the North
and Baltic Seas. The distribution of grain sizes in. the sediments of the
German Bight was fixed; the electric conductivity and the. temperature in
silt was measured in situ by means of a new device. The winter 1960/67
proved poor in ice at the coasts of the Federal Republic of Germany.
Beside the above-mentioned activities, there is the comprehensive
routine work of the DHI; thus * the following periodicals were issued: Win-
terbetonnung der deutschen Küstengewässer (winter buoyage in the German
coastal waters); Gezeitentafeln und -kalender (tide tables and calendars);
Nachrichten für Seefahrer (notices to mariners); Eisbericht'e und Eisüber
sichtskarten (ice reports and general ice charts); Nautisches Jahrbuch
(nautical almanac); the nautical journal "Der Seevart"; Verzeichnis der
Nautischen Karten und Bücher (list of the nautical charts and books); Jah
resbericht des DHI (annual report of the DM); Erdmagnetische Beobachtun
gen (geomagnetic observations); Deutsche Hydrographische Zeitschrift (Ger
man hydrographic journal); Informationen der hydrographischen Dokumentation
(notifications of the hydrographic documentation). As to the special Services
of the DHI> the Nautical Warning Service promulgated 2,73^ notifications; the
