412 



Mr. PETEIE'S Inquiry into the Origin and 



is further remarkable in having its angular head formed of a single stone ; and 

 the second, a semicircular-headed aperture in the Tower of Dysert. 



' 



Moreover, many of the angular-headed apertures have recessed semicircular 

 arches, instead of the more usual horizontal lintels, such arches being sometimes 



formed of a single stone, and at other times of several stones, on the regular prin- 

 ciple of the arch, as in the prefixed example, showing the large aperture placed 



