In like manner, how easily the granitic blocks of Scandinavia could by similar means have been transported across the Baltic!--and at the same time many of the phenomena of drift (a name now given by many geologists to what was formerly called diluvian) might be explained, as shown by Mr Lyell in his account of the Norfolk drift, by the action of floating fields of ice carrying with them sand and gravel, or grating and heaping up the sand and gravel of shoals on which they were beginning to ground, as shown in the examples cited. The long lines of drift and boulders extending from north to south in northern Europe were indeed in all probability the result of the joint operation of the marine current which moved onwards the floating ice, and of the ice itself. In these lines or trainées, two sets have been discovered--one crossing the other at a very acute angle, a circumstance which may possibly be explained by supposing two currents simultaneously running from the north being inflected by local peculiarities into slightly differing directions, and then, on meeting, proceeding in a direction the resultant of the two; the direction of the resultant varying at different epochs according as one or the other current, from varying local causes, possessed the greater or less velocity; if so, the natural result of such meeting currents would be to deposit along their resulting direction lines of drift, to form in this manner shoals on which the floating ice would occasionally ground, and by its load of gravel and boulders assist the work of detritic accumulation.