CONSTRUCTION AND FIRE PROTECTION OF COTTON WAREHOUSES. 25 
Doors in the exterior wall may be of several different types. In 
most instances the sliding* door is to be preferred as it is easy to- 
operate and may be fitted close to the wall. An excellent door of this 
type is shown in Plate XIII, figure 2. Here the door is composed of 
three layers of wood covered with tin so as to resist the action of fire 
from either side. The hardware should be such as to hold the door 
closed even after long exposure to fire. For this reason all hinges, 
track supports, and other hardware should be built solidly into the 
wall. Whether or not doors are locked is a question for the manage- 
ment to decide. Boiling steel doors which slide, or roll up, may be 
used to good advantage where it is desired to provide openings near 
together as for a compress. These doors are extremely neat and 
resist fire well. They have one serious disadvantage for the storage 
compartment in that they are difficult of operation from the outside, 
and it is necessary for the person operating them in this way to stand 
in the opening until the door is entirely raised. The difficulty here in 
case smoke or flame had to be contended with is apparent. But for 
the large compress compartment, with its entrance doors of some other 
type, these doors are excellent. Photographs of installations of these 
doors are shown in figure 1, Plate XIII. Swinging doors are usually 
less desirable than sliding doors as the former are somewhat in the 
way of trucking and are put out of repair more easily. 
FIRE BOORS. 
Fire doors in the division fire wall should afford high resistance 
to heat. The construction is similar to those described for the ex- 
terior wall, with the addition of requirements for automatic closing 
in case of fire. There are many types of fire doors which may be pur- 
chased ready to install. All of the doors illustrated by Plate XIY are 
what is termed "tin-clad" (a wood core covered with tin) except 
that shown in figure 2, this being a steel rolling door which may be 
installed in the several manners shown. This door is very neat in 
appearance and affords good protection. Doors of the sliding or 
hinged type are also made of sheet steel corrugated and riveted to a 
framework of steel as shown in Plate XY, figure 1. The tin-clacl 
door referred to is an excellent door for an opening in a division fire 
wall. It should consist of three layers of boards, each not less than 
thirteen-sixteenths of an inch thick. The tin covering should be ap- 
plied independently of the use of solder, the joints being securely 
locked and nailed. There are many details to be followed in the con- 
struction to insure the best resistance to fire and positive movement 
in closing. 1 
1 The door can be built locally by a good tin worker and carpenter, or it can 
be bought ready made. The latter course may be more economical and is nearly 
