characterize most of the German Gothic work of the late fourteenth and of the fifteenth century. This is exemplified in the slender mullions of Ulm, the lofty and complicated spire of Strasburg, and the curious traceries of churches and houses in Nuremberg. +PERIODS.+ The periods of German mediæval architecture corresponded in sequence, though not in date, with the movement elsewhere. The maturing of the true Gothic styles was preceded by more than a half-century of transition. Chronologically the periods may be broadly stated as follows: THE TRANSITIONAL, 1170-1225. THE EARLY POINTED, 1225-1275. THE MIDDLE OR DECORATED, 1275-1350. THE FLORID, 1350-1530. These divisions are, however, far less clearly defined than in France and England. The development of forms was less logical and consequential, and less uniform in the different provinces, than in those western lands. +CONSTRUCTION.+ As already remarked, a tenacious hold of Romanesque methods is observable in many German Gothic monuments. Broad wall-surfaces with small windows and a general massiveness and lowness of proportions were long preferred to the more slender and lofty forms of true Gothic design. Square vaulting-bays were persistently adhered to, covering two aisle-bays. The six-part system was only rarely resorted to, as at Schlettstadt, and in St. George at Limburg-on-the-Lahn (Fig. 139). The ribbed vault was an imported idea, and was never systematically developed. Under the final dominance of French models in the second half of the thirteenth century, vaulting in oblong bays became more general, powerfully influenced by buildings like Freiburg, Cologne, Oppenheim, and Ratisbon cathedrals. In the fourteenth century the growing taste for elaboration and rich detail led to the introduction of multiplied decorative ribs. These, however, did not come into use, as in England, through a logical development of constructive methods, but purely as decorative features. The German multiple-ribbed vaulting is, therefore, less satisfying than the English, though often elegant. Conspicuous examples of its application are found in the cathedrals of Freiburg, Ulm, Prague, and Vienna; in St. Barbara at Kuttenberg, and many other important churches. But with all the richness and complexity of these net-like vaults the Germans developed nothing like the fan-vaulting or chapter-house ceilings of England. [Illustration: FIG. 139.--ONE BAY OF CATHEDRAL OF ST. GEORGE, LIMBURG.]