For two days we are going to follow the valley where the river slowly coils its long bends through the wheat fields and the poplars. The low hills, covered with forests, lie in the distance and never come near enough to force the Oise to sudden detours. This river is not like the Marne, incessantly turned aside by the spur of a hill. It flows indolently under a pale horizon, in a vast landscape whose shades are infinitely delicate, and whose lines are infinitely soft. It bears silent barges through the fertile plains. Daughter of the north, it reflects in its clear green waters villages of brick. The smoke of workshops mingles with the mist-banks of its sky. At night the lights of the glass furnaces brighten its banks. By talking with the men who drive their horses upon the towpath, it is easy to guess that the Oise is born in Belgium. Bell-towers dot the valley on both banks of the river. That of Montataire rises above the trees of a park at the top of a bluff. The church possesses an exquisite portal surmounted by a frightfully mutilated bas-relief of the Annunciation; but how much grace the draperies still possess! It is useless to stop at Creil, since a barbarous municipality thought it advisable to pull down the church of Saint Evremont, one of the most beautiful specimens of the architecture of the twelfth century. The people of Nogent-les-Vierges are not barbarians: they have preserved their church. It is not as pure in style as that of Saint Evremont. But its belfry--terribly restored--is adorned with original details. The rectangular choir, which the thirteenth century added to the Romanesque nave, possesses a rare elegance, with its slender pillars. What a diversity there is in the creations of Gothic architecture! How inventions in construction permitted infinite variation in the plans of churches! It is only by thus traversing the countrysides of France that one can admire the abundant imagination of the builders of the thirteenth century. There are many churches, especially in the north, which, like that of Nogent-les-Vierges, possess a choir terminated by a flat wall. But the type is diversified from edifice to edifice. Open a manual of archæology; take the most recent and the most complete of all, that of M. Enlart, and you will observe what difficulty the author has in classing and characterizing such work, after the last years of the twelfth century. At no other period was architecture so profoundly individual an art. We may say that every building was then original, not only in the details, but especially in the plan.