Now as to certain general considerations in relation to the appropriate and logical use of ceramics in the construction and adornment of buildings, exterior and interior. In our northern latitudes care should be taken that ceramics are not used in places and in ways where the accumulation of snow and ice render the joints subject to alternate freezing and thawing, for in such case, unless the joints are protected with metal, the units will work loose in time. On vertical surfaces such protection is not necessary; the use of ceramics should therefore be confined for the most part to such surfaces: for friezes, panels, door and window architraves, and the like. When it is desirable for æsthetic reasons to tie a series of windows together vertically by means of some "fill" of a material different from that of the body of the wall, ceramics lend themselves admirably to the purpose--better than wood, which rots; than iron, which rusts; than bronze, which turns black; and than marble, which soon loses its color and texture in exposed situations of this sort. On the interior of buildings, the most universal use of ceramics is, of course, for floors, and with the non-slip devices of various sorts which have come into the market, they are no less good for stairs. There is nothing better for wainscoting, and in fact for any surface whatsoever subject to soil and wear. These materials combine permanent protection and permanent decoration. But fired by the zeal of the convert the use of ceramics may be overdone. One easily recalls entire rooms of this material, floors, walls, ceilings, which are less successful than as though a variety of materials had been employed. It is just such variety--each material treated in a characteristic, and therefore different way--that gives charm to so many foreign churches and cathedrals: walls of stone, floors of marble, choir-stalls of carved wood, and rood-screen of metal: it is the difference between an orchestra of various instruments and a mandolin orchestra or a saxaphone sextette. Ceramics should never invade the domain of the plasterer, the mural painter, the cabinet maker. Do not let us, in our zeal for ceramics, be like Bottom the weaver, eager to play every part. Ceramics have, as regards architecture, a distinct and honorable function. This function should be recognized, taken advantage of, but never overpassed. They offer opportunities large but not limitless. They constitute one instrument of the orchestra of which the architect is the conductor, an instrument beautiful in the hands of a master, and doubly beautiful in concert and contrast with those other materials whose harmonious ensemble makes that music in three dimensions: architectural art. SYMBOLS AND SACRAMENTS