Mean Sea-Level ¹

Abstract

THE science of oceanography is slowly coming into its own, and it has advanced greatly in the last twenty years; but still, of those who think of it at all, many people know very little what it is. It is looked upon, often enough, as an easy, descriptive science, a small part of a simple, descriptive geography. But if this be true at all, it is a very small part of the truth; for the great problems of oceanography are physical problems, to be approached by mathematical methods, and soon involving us in difficult questions of hydrodynamics, and other difficulties besides. In the elementary task of the exploration of the sea Englishmen have taken a large, perhaps a lion's, share; in one special part of scientific hydrography, ¦ the theory of the tides, they have done a great deal, for such names as Lubbock, Whewell, Airy, Kelvin, and George Darwin come at once to our minds. But in other parts of the subject, and in recent times, we have done less; and the Scandinavian countries especially have done a great deal more. Bierknes, Witting, Otto Pettersson, Sandstrom, Fridjof Nansen, Helland-Hansen, Madsen, and De la Cour are only a few names of men who, from Denmark to Finland, have studied the hydrographical phenomena of the Baltic or the wider problems of hydrography.