This building is on the rear, or north side, of Memorial Hall, and is the first portion of the fine-art department that meets the eye of one coming from Horticultural Hall. It is of comparatively temporary character, being built of brick instead of the solid granite that composes the pile in front of it. Its architectural pretensions are of course inferior. It is the youngest of all the exposition buildings, the present spring witnessing its commencement and completion. The drying of such green walls in such manner as to render them safe for valuable pictures has been compassed by the use of "asbestos" brick, which is said to be fire- as well as water-proof. Failure in this regard would be of the less moment, inasmuch as a great proportion of the contents will be drawings and engravings. In interior plan the extension will closely imitate the main building. Memorial Hall, as its name implies, contemplates indefinite durability. What Virginia and Massachusetts granite, in alliance with Pennsylvania iron, on a basis of a million and a half of dollars, can effect in that direction, seems to have been done. The façade, designed by Mr. Schwarzmann, is in ultra-Renaissance; the arch and balustrade and open arcade quite overpowering pillar and pediment. The square central tower, or what under a circular dome would be the drum, is quite in harmony with the main front so tar as proportion and outline are concerned; but there is too much blank surface on the sides to match the more "noisy" details below it. This apart, the unity of the building is very striking. That its object, of supplying the best light for pictures and statuary, is not lost sight of, is evidenced by the fact that three-fourths of the interior space is lighted from above, and the residue has an ample supply from lofty windows. The figures of America, Art, Science, etc. which stud the dome and parapet were built on the spot, and will do very well for the present. The eagles are too large in proportion, and could easily fly away with the allegorical damsels at their side.