Geophysical Abstracts 152 January-March 1953

GRAVITY 11
14198. Aslakson, Carl I. Relative geoidal undulations from deflections of the
vertical. Am. Geophys. Union Trans., v. 34, no. 1, p. 1-10, 1953.
Shoran trilateration in the Bahama Islands permits the determination of the
deflection of the vertical with considerable accuracy. A striking correlation be­
tween deflections observed to date and both ocean-bottom gradients and free-air
anomaly gradients suggests that deflection observations may be used in com­
puting undulations of the geoid. Tanni's solution of the worldwide undulations
indicates a geoidal rise of 3 meters between Cape Canaveral, Florida, and the
ocean area east of southern Florida; the same value is obtained by the de­
flection method. M. G. R,
OBSERVATION OF GRAVITY AND GRAVITY SURVEYS
14199. Sanders, P. Liaison gravimetrique Belgique-Congo beige [Gravimetric
tying between Belgium and Belgian Congo]: Inst. Royal Colonial Beige
Bull., tome 23, p. 905-918, 1952.
Absolute measurements of gravity were made at three base stations in the
Belgian Congo, using bronze pendular apparatus of the Uccle observatory. The
values obtained were: Leopoldville, 977919.0 ±0.9 ingal; Elisabethville, 977900.8±
0.7 mgal; Costermansville, 977601.5 ±0.8 rngal. 8. T. V.
14200. Coron, Suzanne. Valeur de la pesanteur a Paris determines a 1'aide des
liaisons Internationales europ^ennes [Value of gravity at Paris deter­
mined with the aid of European international ties]: Bull. geod., no. 16,
p. 118-139, 1950.
The most probable value of gravity at Paris in the Potsdam system, calculated
on the basis of old pendulum measurements and more modern gravimetric ties
is indicated as not more than 980.9440 gals. The old value of 980.9430 gals will
be retained as base of the French network. M. O. R.
14201. Volet, Charles. MSsure de 1'acceleration due a la pesanteur au Pavilion
de Breteuil [Measurement of the acceleration of gravity at the Pavilion
de Breteuil]: Acad. Sci. Paris Comptes Rendus, tome 235, no. 6, p.
442-444, 1952.
By the direct determination of the law of free fall of a body in vacuum, a value
of g at "Point A" (48°49'45" N. lat, 2°13'14" E. long.) has been found which
is 24 mgal less than that deduced in the Potsdam system. The average of 18
determinations was 980.916 gals. M. (7. R.
14202. Tomaschek, R. Tidal gravity observations at Winsford (Cheshire) :
Royal Astron. Soc. Monthly Notices, Geophys. supp. v. 6, no. 6, p. 372-
382, 1952.
Tidal observations were made during April 1951 in the Imperial Chemical
Industries, Ltd. salt mine at Winsford. The gravimetric factor was determined
for both the over-all values and the principal harmonic constituents. There was
no significant phase difference between the theoretical and observed curves.
G" was determined as the weighted mean of regression coefficients of observed
values upon the immediately nomographically determined values for hourly and
half-hourly periods. The values of G' at Winsford is 1.20±0.04. m Values of G'
determined for constituents of the harmonic analysis yielded a mean of 1.20, an
excellent agreement. The value is somewhat higher than that for Kirklington
and Peebles (see Geophys. Abs. 13809, 13810. P. E. B.