in the thirteenth century; that the central tower was rebuilt in the fourteenth century, and that the nineteenth century saw a great deal of necessary work done. Remembering this, you will surely depart reluctantly, convinced that of all our English books in stone none contains more chapters than that entitled Peterborough Cathedral, that in no edifice can the student of architecture who inspects with the advantage of special knowledge, or the fairly cultivated man who lacks that special knowledge, find more details of genuine charm and interest. Here you can trace developments, early Norman vaulting in the aisles, exquisite fan-vaulting--it is peculiar to England--in the choir, clustered piers to columns. Here you may follow the differences in character and arrangement between a monastic cathedral, such as Peterborough was, served by regular clergy and monks, and one of the old foundation, like St. Paul's, which, being served by secular clergy, was not affected by the reforms of Henry VIII. You may see, too, traces of the iconoclastic zeal of Cromwell's followers, often credited with the misdeeds of others. In spite of them, too, you may realize, not more forcibly than elsewhere perhaps, but still in full force, that which has been remarkably well put by Professor Banister Fletcher and Mr. Banister F. Fletcher in their _Comparative Architecture_. "The place in the national life which the mediæval cathedrals occupied was an important one, and must be realized if we would understand how they were regarded. In the absence of books, and of people able to read them, cathedrals were erected and decorated partly as a means of popular education, the sculpture and the painted glass reflecting the incidents of Bible history from the Creation to the redemption of mankind, the sculptured forms and brilliant colouring rendering them easily understood by the people. The virtues and vices, with their symbols, were also displayed, either in glass or statuary, along with their reward or punishment. Saints and angels told of the better life, and the various handicrafts, both of peace and war, were mirrored in imperishable stone or coloured glass. They, to a large extent, took the place in our social state since occupied by such modern institutions as the Board School, Free Library, Museum, Picture Gallery, and Concert Hall. They were the history books of the period. Architecture then as now was also the grand chronicle of secular history, past and present, in which Kings, Nobles, and Knights were represented."