 The facts indicate that the continent of North America had its surface near tide-level, part above and part below it (p.196); and this will probably be proved to be the condition in Primordial time of the other continents also.And, if the outlines of the continents were marked out, it follows that the outlines of the oceans were no less so".Dana was enormously influential in America – his "Manual of Mineralogy" is still in print in revised form – and the theory became known as "Permanence theory".