THERE is no topographical division of Europe which more readily defines itself and its limits than the Rhine valley from Schaffhausen to where the river empties into the North Sea. The region has given birth to history and legend of a most fascinating character, and the manners and customs of the people who dwell along its banks are varied and picturesque. Under these circumstances it was but to be expected that architectural development should have expressed itself in a decided and unmistakable fashion. One usually makes the Rhine tour as an interlude while on the way to Switzerland or the Italian lakes, with little thought of its geographical and historical importance in connection with the development of modern Europe. It was the onward march of civilization, furthered by the Romans, through this greatest of natural highways to the north, that gave the first political and historical significance to the country of the Rhine watershed. And from that day to this the Rhenish provinces and the Low Countries bordering upon the sea have occupied a prominent place in history. There is a distinct and notable architecture, confined almost, one may say, to the borders of the Rhine, which the expert knows as Rhenish, if it can be defined at all; and which is distinct from that variety of pre-Gothic architecture known as Romanesque.