DOOES 



97 



mortise lock (Fig. 102). The latter, on account of its being mortised 

 into the door, is much neater than the former. In ordering, care should 

 be taken to distinguish between right-hand and left-hand locks. The 

 difference is illustrated by Fig. 103. A rim lock is fixed on the inner 

 side of the door, i.e. on the side towards which the door opens. The 

 doors in Fig. 103 appear therefore as they would to a person looking 

 from the inside of the apartments to which they belong. 



Sliding Doors. — In some positions, such as between a bull-box and 

 its exercise yard, or in exposed windy situations, sliding doors are to be 

 preferred to swing doors. 



Fig. 104. 



Fig. 104 illustrates a "single" sliding door which, for example, 

 could be used between the bull-box and exercise yard shown in Fig. 147. 



Figs. 105 a, b, and c illustrate a " double " sliding door, used when 

 a wide opening is required. 



The doors are framed, braced, and ledged, and their construction 

 has already been described (p. 90). The manner in which they are 

 suspended, etc., will be evident from the accompanying figures (Figs. 

 104, 105 a, b, and c, and 106). Each door runs on a 3" by f" wrought 

 iron runner-bar, which is bolted to two 9" by 3" deals built into the 

 walls and crossing the opening for the door. These deals are also bolted 

 to the walls, as shown in Fig. 106, and the bolts used to bolt on the 

 runner-bar serve also to hold the two deals together. The bottom of 



II 



