daily be seen. Iron doors over wooden sills, with the flooring boards
extending through from one building to the other, are common occurrences.
We frequently find otherwise good doors hung on wooden jambs by ordinary
screws. Sliding doors are frequently hung on to woodwork, and all
attachments are frequently so arranged that they would be in a very short
time destroyed by fire, and cause the door to fall. In case of fire, a
solid iron door offers no resistance to warping. In an iron lined door,
on the contrary, the tendency of the sheet iron to warp is resisted by
the interior wood, and when this burns into charcoal, it still resists
all warping tendencies. I have seen heavily braced solid iron doors
warped and turned after a fire, having proved themselves utterly
worthless. It is needless to say that when wooden doors are lined, they
should be lined on both sides; but frequently we find so-called fireproof
doors lined on one side only.

Good doors are frequently blocked up with stock and other material, so
that in case of fire they could not be closed without great exertion; or
they have been allowed to get out of order, so that in case of fire they
are useless. This has been so common that it has given rise to the
jocular expression of insurance men, when they are told that a fire door
exists between the two buildings, "Warranted to be open in case of fire."
The strictest regulations should exist in regard to closing the fire
doors nightly. Frequently we find that although the fire door, and its
different parts, are correctly made, there are openings in the wall which
would allow the fire to travel from one building to the other, such as
unprotected belt and shaft holes. That a fire door may be effective, it
must be hung to the only opening in the wall.

The greatest care must be exercised to keep joists from extending too far
into the wall, so as not to touch the joists of the adjacent building,