Arthur Holmes - speculated on mantle convection and that this drives continental drift. Spins 4 times faster than outer and 100,000 times faster than continents move. Often thought to be the first to suggest continental drift, but really only noted similarity in shapes of continents. 1908 F. B. Taylor suggested that moon once closer to earth and that gravitational forces would move continents. 1910 Alfred Wegener and others found evidence of Africa and South America being together.
Continents move over or through ocean basins.
Above idea not generally accepted because no mechanism. Arthur Holmes - speculated on mantle convection and that this drives continental drift. Still knew little about oceans. There were many other issues that geologists were trying to explain such as the distribution of mountain ranges and change in the types of sediments near continental margins, and the evidence for continental drift. Harry Hess was a submarine commander.