PACIFIC EXPLORATION: C SCHUCHERl 
407 
ation for the Advancement of Science for a grant used in connection 
with the 1915 measurements. 
1 Bauer, L. A., On gravity determinations at sea, Amer. J. Set., 31, 1 (1911). Hecker's 
remarks on ocean gravity observations, Amer. J. Sci. 33, 245 (1912). 
2 Bowie, Wm., Isostasy and the size and shape of the earth, Science, 39, 705 (1914). 
"Hayford, J. F., these Proceedings, 2, 394 (1916). 
* For a description of the apparatus employed by Hecker and a summary of his ocean 
measurements, see Hecker, O., Bestimmung der Schwerkraft auf dem Schwarzen Meere und, 
an dessen Kuste sowie neue Ausgleichung der Schwerkraf tmessungen aud dem Atlantischen, 
Indischen, und Groszen Ozean, Zentralhur. Internal. Erdmessung, VerofentUchungen 
Berlin, N. F., Nr. 20 (1910). 
^Washington, D. C, Bull. Bur. Standards, 3, 663 (1907). 
* This principle has already been employed by Mascart, [Paris, C. R. Acad. Sci., 95, 631, 
1882], who used a sealed-off barometer of the U-tube type. The temperature was not 
controlled, and volume and pressure were both variable. The gas volume had therefore 
to be measured, the pressure corresponding to the observed temperature and volume cal- 
culated, and finally reduced to standard conditions. 
^ This procedure now seems undesirable, since Fernet has observed a departure of 0°.01C. 
from the true zero when the bulb of a thermometer is surrounded by artificial ice freely 
drained, due to the ice being undercooled. (See Fernet, J., Sur les moyens d'eliminer I'in- 
fluence de la variation des points fixes des thermometres a mercure. Travaux. Bur., Inter- 
national des Poids et Mesures, 1881, second partie.) In the writer's measurements, ice 
was added in small quantities at frequent intervals so as to keep the tanks completely filled, 
and remained in the apparatus for several hours before melting sufficiently to sink to the 
level of the gas chamber. It is consequently doubtful whether the effect observed by Fer- 
net influenced the measurements, but it is a possible source of error which can be avoided 
by keeping the interstitial spaces filled with water. 
^Phil. Trans. R. Soc, London, 196, 205 (1901). 
^ Loc. cit. 
^° The above procedure was not followed strictly in the trials of the apparatus which have 
so far been made at sea, due to the difficulty of following the observing tube with the eye 
when the ship is roUing in a heavy sea. Experience shows however that such an arrange- 
ment is necessary if observations are to be made in rough weather, and the difficulty in ob- 
serving can apparently be met by a modification of the viewing apparatus. 
" See Hecker, loq. cit. 
THE PROBLEM OF CONTINENTAL FRACTURING AND 
DIASTROPHiSM IN OCEANICA 
By Charles Schuchert 
DEPARTMENT OF GEOLOGY, YALE UNIVERSITY 
Read before the Academy, April 17, 1916. Received, June 1, 1916 
Paleogeographic studies during the past thirty years have been 
developing the hypothesis that the ancient continental platforms were 
arranged latitudinally rather than longitudinally as they are now, and, 
further, that their areal extent, including their emergent and submerged 
portions, was greater than at present. It appears that vast land-masses 
have been fractured, broken up, and more or less permanently taken 
