CONSTRUCTION AND FIRE PROTECTION OF COTTON WAREHOUSES. 27 
Fire doors for protection of openings in a division wall should 
always be arranged to close automatically in case of fire. The ar- 
rangement should be such that the door is held open, against its 
tendency to close from gravity, by a device which is affected by 
heat in such manner asi to release the door and permit it to close 
in case of fire. The arrangement may be such that the door normally 
is closed but may be held open by a special hook designed to release 
the door should fire occur. All self-closing doors should provide 
this automatic combination, as otherwise there is danger of the door 
being purposely obstructed and then overlooked until a serious fire 
loss has supplied a costly reminder. 
fire. The pulley over which the chain passes must be sufficiently high to 
insure that the door is entirely closed before the weight reaches the floor. 
The weights used for holding open either type of sliding door (shown to the 
right of the doors) should be adjusted to balance the door exactly and so 
allow it to be closed by hand. The self-closing feature may be added to both 
of these doors by omitting the weights which hold the door open. When this 
is done the fusible link should be retained and a hook provided to secure it to 
the edge of the opening when it is desired to hold the door open. Unless the 
link and hook are provided, doors should never be self-closing, as they fre- 
quently will be obstructed " temporarily " for the movement of goods and then 
forgotten. If the hook is provided, it will be used as the easiest way of hold- 
ing the door open, and if the door is, by chance, left open it will still close 
automatically in ease of fire. It should be noted that the hardware for these 
doors provides a roller at the bottom of the door for holding it close to the 
wall on one side, while the door is held firmly when closed by the heavy iron 
bumpers on the other side. These doors show three hangers, the center hanger 
serving to hold the door against buckling from heat. Two hangers are suffi- 
cient for doors not exceeding 6 feet in width, while three hangers are required 
for wider doors. Goods should never be piled again the door. To guard 
against this it is sometimes desirable that a substantial slatted guard be 
provided. 
Drop doors, or those vertically sliding, such as is shown by figure 4, Plate 
XIV, may be used to advantage in case obstructions such as pilasters or 
buttresses interfere with the horizontally sliding door and where the height 
of story is sufficient. In the illustration the weight shown on the left is con- 
nected by a cord passed through two pulleys to the fusible link placed at the 
bottom edge of the door, and when the weight is released the door closes. 
The closing is made gradual by the large counter weight or balance shown 
on the right. This door may be operated by hand, though it is not opened as 
readily as the horizontal sliding door, and is particularly difficult to open 
after the closing has been automatic. Furthermore, it presents some hazard 
to life if it should drop while a person were passing under it, though this 
danger is reduced by the large counterweight. 
The swinging door shown by figure 6, Plate XIV, is satisfactory though 
it is better suited to small than large openings It may be arranged to be 
self-closing or to close automatically, but care should be taken that the 
fusible link used is placed in position to be reached by drafts of air through 
the opening. For this door the hardware, unlike that of the sliding or drop 
doors, must provide substantial latches which will hold the door securely 
when closed. 
