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25.726. Jahresbericht des Deutschen Hydrographischen Instituts 1970/71 
Draught route soundings. The four charts were published in the meantime as 
British Admiralty Chart No. 5059 and as supplement to Vol. I of the German Tide 
Tables. Detailed predictions for 10 new places of reference were added to Vol. II 
of the Tide Tables (areas other than European). 
Since January 1971, the tidal observations of the Scottish-English coast are being 
continuously transmitted. Thus, motions of water masses penetrating from the 
Atlantic into the North Sea, in addition to the tides, which often increase or de 
crease the water levels in the German Bight by as much as 0.5 m can be traced 
more easily and taken into consideration for the daily water level predictions or 
storm surge warnings. 
In the course of the year 1971, the GHI put a modern high-speed computer H 632 
of Messrs. Honeywell into operation for comprehensive scientific computations. 
This computer has magnetic plates as external storage. 
The Geomagnetic Observatory Wingst was responsible for the 
correspondence concerning the standardization of geomagnetic base values of 14 
European observatories. Within the framework of the working group “Ionosphere“ 
of the German geophysical institutes, the observatory continued to participate in 
the prediction of the quality of radio communications. 
At the General Assembly of the International Astronomical Union in Brighton in 
August 1970, the GHI was represented in three commissions. These dealt especially 
with the question of reconciling the astronomical definition of the legal time with 
the new atomic definition of the physical unit of time (second). The GHI Time 
Service continuously registered the time difference between the reading of its 
caesium beam atomic clock and the pulse phases of the Loran-C-transmitter at 
Sylt to an accuracy of 0.1 l^s. Such measurements are employed in world-wide 
intercomparisons with very high precision of atomic clocks. Besides, numerous 
mechanic and electronic chronometers of ships were tested. 
Apart from the type tests provided by Law, the Hamburg Department and the nine 
GHI agencies in other ports tested more than 100 000 nautical instruments and 
gave expert advice for the installation of instruments. From nautical-technical 
investigations suggestions were gained for the improvement of shipborne nautical 
instruments and devices. 
Since 1 September 1970, Germany and the Netherlands have been mutually adopt 
ing their Approval Certificates for navigation lights (in cases of retesting only) and 
magnetic compasses. An agreement was also reached with Norway for the full 
mutual adoption of Approval Certificates for magnetic compasses from 1 November 
1970. 
The new text of the approval and testing conditions for navigation lights was pub 
lished in the “Bundesanzeiger" in connection with the new German Regulations 
for Preventing Collisions on the German Waterways and came into force on 26 May 
1971. With the approval of the Federal Ministry of Transport (BMV), rules for ap 
pointing qualified persons as GHI assistants were issued and published in the 
“Verkehrsblatt“ of the Ministry of Transport.