Several of these have been drawn by Lepsius, and are engraved in his work; but, as no text accompanies them, and the drawings are not on a sufficient scale to make out the hieroglyphics, where any exist, their date cannot now be ascertained. Consequently, these examples cannot yet be used as the foundation of any argument on the subject, though the curved form of the roofs in the Third Pyramid would alone be sufficient to render it more than probable that during the period of the 4th dynasty the Egyptians were familiar with this expedient.[99] At Beni-Hasan, during the time of the 12th dynasty, curvilinear forms reappear in the roofs (Woodcut No. 16), used in such a manner as to render it almost certain that they are copied from roofs of arcuate construction. Behind the Rameseum at Thebes there are a series of arches in brick, which seem undoubtedly to belong to the same age as the building itself; and Sir G. Wilkinson mentions a tomb at Thebes, the roof of which is vaulted with bricks, and still bears the name of Amenoph I., of the 18th dynasty.[100] The temple at Abydus, erected by Rameses II., shows the same peculiarity as the tombs at Beni-Hasan, of a flat segmental arch thrown across between the stone architraves. In this instance it is also a copy in stone, but such as must have been originally copied from one of brick construction. There is also every reason to believe that the apartments of the little pavilion at Medeenet Habû (Woodcuts Nos. 32 and 33) were covered with semicircular vaults, though these have now disappeared.[101] In Ethiopia Mr. Hoskins found stone arches vaulting the roofs of the porches to the pyramids, perfect in construction, and, what is still more singular, showing both circular and pointed forms (Woodcut No. 105). These, as before remarked, are probably of the time of Tirhakah, or at all events not earlier than the age of Solomon, nor later than that of Cambyses. [Illustration: 101. Section of Tomb near the Pyramids of Gizeh.] In the age of Psammeticus we have several stone arches in the neighbourhood of the pyramids; one, in a tomb at Sakkara, has been frequently drawn; but one of the most instructive is that in a tomb discovered by Colonel Campbell (Woodcut No. 101), showing a very primitive form of an arch composed of 3 stones only, and above which is another arch of regular construction of 4 courses. In his researches at Nimroud, Layard discovered vaulted drains and chambers below the north-west and south-east edifices, which were consequently as old as the 8th or 9th century before our era, and contemporary with those in the pyramids of Meroë. They were of both circular and pointed forms, and built apparently with great care and attention to the principles of the arch (Woodcut No. 102). [Illustration: 102. Vaulted Drain beneath the South-East Palace at Nimroud.]