The penetrations and pendentives are richly embellished with a great variety of ornament, both conventional and otherwise. The treatment differs in different corridors, however, on account of the varying relative position of the paired columns which support the arcade--from which results first a series of wide and then a series of narrow pendentives. Where the former occur--in the West and East Corridors--they are ornamented with the decorations of Mr. Shirlaw and Mr. Barse; while the narrower pendentives on the north and south carry simple medallions and tablets, and Mr. Reid’s and Mr. Benson’s paintings find place in the arabesque of the ceiling vault and in circular frames along the wall beneath. The balance is restored, however, by introducing a series of medallions, corresponding to Mr. Benson’s and Mr. Reid’s, though smaller and of less importance, in the vaults east and west, and by ornamenting the penetrations in the side corridors with greater richness and elaboration. [Illustration: THE NORTH CORRIDOR, SECOND STORY, MAIN ENTRANCE HALL. SHOWING DECORATIONS BY GEORGE W. MAYNARD AND ROBERT REID.] =The Printers’ Marks.=--The most interesting decoration of the penetrations, however, is a series of “Printers’ Marks” which is continued through all four corridors. Altogether there are fifty-six of them--sixteen in each of the side corridors, ten in the West Corridor, and fourteen in the East Corridor. They are painted in black outline, and are of a sufficient size, averaging about a foot and a half in height, to be easily made out from the floor. By a printer’s mark, it should be explained, is meant the engraved device which the old printers used in the title-page or colophon of their books, partly as a kind of informal trade-mark guarding against counterfeited editions, and partly as a personal emblem, such as a publisher of good standing would like to see on a long list of worthy books. For this latter reason, and in order to be able to add an interesting piece of ornament to the title-page, the mark has been revived of late years by a considerable number of modern publishing and printing houses. Very often, as the visitor will see, the printer’s mark is, in its way, a really beautiful piece of design; many have an interest as being associated with the reputation of a famous printer like Caxton, or Aldus, or Elzevir; while others depend mainly for their point upon some special symbolical meaning, very frequently taking the form of an illustrated pun. Thus, in the West Corridor, the mark of Lotter--which means “vagrant” in German--is a mendicant supplicating alms. In the South Corridor, the mark of Geoffroy Tory commemorates the death of his little daughter--the broken vase, with a book symbolizing the literary studies of which she had been fond.