Page:The castellated and domestic architecture of Scotland from the twelfth to the eighteenth century (1887) - Volume 2.djvu/220

 FOURTH PERIOD 204 Z PLANS FOURTH PERIOD Z PLANS. The next series of castles we have to consider are those built on what we have ventured to call the Z plan. These consist of the usual oblong main block,, representing the original keep, with a tower added at two of the diagonally opposite angles. In the "double tower" plans, described above, we have seen the tendency manifested to construct houses so that one part should protect another. The general use of fire-arms seems to have encouraged this idea, and led to the erection of a second tower at the opposite angle of the main building. In the case of the " double tower" plan, only the two faces of the main block adjoining the tower were protected from it ; but in the Z-planned houses the whole of the four walls of the main building are covered and defended from shot- holes in the two diagonally opposite towers. The two towers also add considerably to the internal accommodation of the house, giving, in addition to the apartments in the main block, two small rooms on each floor, instead of the single small room provided by the L plan and the " double tower " plan. One of the towers is frequently made available for containing the principal staircase to the first floor, staircases to the upper floors being carried up in circular turrets corbelled out in the re-entering angles of the two towers, so as to provide separate accesses to all the different rooms. The towers are sometimes round, and sometimes square or oblong, and occasionally, as at Castle Fraser, one tower is circular and the other square. The mode of finishing the towers at the top varies greatly, and forms one of the most marked and pleasing features of this design. In some of the plainer houses of the Z plan, such as Terpersie, the towers are simply covered with a slated roof. In other instances, such as Glenbucket, Drochil, Claypotts, etc., the towers are either built square from the foundation or are corbelled out to the square, and are finished with a plain coupled roof and crow-stepped gables. At Kilcoy one tower is brought to the square and finished in this way, while the other is carried up of a round form to the top, and was covered in with a tall conical roof. In other examples, such as Notland, the towers are completed on top with parapets resting on bold corbel tables, behind which there is a parapet walk, provided with bartizans on the angles, for defensive purposes. At Castle Fraser and Fordouii the same idea is carried out in a more fanciful and picturesque manner, and the two towers are treated each in a different way. An immense variety of design is thus introduced into this form of plan, the arrangements of which form the motives of some of the most interesting designs amongst our Scottish castles and mansions.