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Section IVGravimetry
1. The I.A.G. having received the report of Commission IX, already
published in the Bulletin Géodésique no. 31, gives General approval to
the resolutions made by the International Gravity Commission at their
meeting in Paris, notes with satisfaction that several of these recom
mendations have already been carried out.
However, after reexamination of the Paris resolution III, it has
been decided to put forward the following modifications
M'Bour (50 km North of Dakar) instead of Dakar
Vancouver (Canada) instead of Victoria (Canada)
LisbonneMadrid instead of Lisbonne
(both these last stations can be occupied by observers).
The I.A.G. notes with pleasure that the International Gravity Bu
reau is in a position to provide information concerning international
and national fundamental stations and strongly recommends that all
overseas who contemplate making gravimetric comparisons involving
such stations should communicate with the Bureau.
2. The I.A.G. having received the report of Commission X on the
connections between absolute measures stations, decides that the study
group should be maintained for the next three years under the chair
manship of Prof. Morelli to continue the work already begun
authorizes the chairman of the study group to enlarge the mem
bership mainly by the inclusion of persons actually engaged in making
absolute determination of gravity.
3. The I.A.G. considering that an accurate knowledge of the abso
lute value of gravity is of primary importance for the establishment
of standards such as weight, temperature and electrical units and for
geodetic purposes such as precise levelling and that neither univer
sally acceptable standards nor uniformity in geodetic operations can
be realized unless all nations adhere to the same gravimetric system
considering that all existing gravity determinations are in fact based
on a value at the fundamental station at Potsdam which now appears
to be some 10 to 20 milligals too largeconsidering that for many
geodetic purposes the value of this correction is of no practical im
portance although it can lead to appreciable errors in other kind of
physical measurementsrecommends
1) that, in fields where an accurate absolute value of gravity is
not required, the value as given by the Potsdam system should continue
be used;
2) that in the hope that final results for absolute measurements
will be available within a few years, all possible assistance should be
given to those engaged in these determinations and in particular that a
high priority should be given to gravimetric interconnections between
those stations at which the determinations are being made;
3) that countries which are not at present members of the Associa
tion should be invited to cooperate in establishing a world wide gravity
network suitable for all scientific applications.
