39
On the floor of the godown under the hole were fragments of a Chinese stove or "chatty". The flue pipe appeared to have run downwards to godown ceiling level, where it had originally been blocked by a thin covering of cement floated over the hole. Two side holes or entrances to this pipe were discovered in the upstairs flats.
Water was poured through the pipe from first floor level in order to discover whence it led, and a great quantity of soot and miscellaneous rubbish descended; this appeared to have been blocking the pipe.
It was therefore concluded that the fire had cracked away the cement and exposed the hole, allowing some of the accumulated rubbish in the pipe-end to fall; the theory was accordingly abandoned.
(c) Theory of ignition by human agency.
All godown doors were found locked, and no bodies were found inside the godown. No pieces of any suspicious mechanism or similar material were found.
There is, accordingly, no evidence to support this theory.
(d) Theory of ignition through the agency of Calcium cyanamide.
Stack 41 (on
This theory is only included for the sake of completeness. Plan No. 1) consists of calcium cyanamide, a synthetic fertilizer which gives off a small quantity of acetylene gas in contact with damp air.
The theory that such gas might have become ignited outside the godown is most unlikely, as in that case an explosion would have occurred throughout the godown, or at the doors.
(e) Theory of ignition by the agency of impure caustic soda.
Ordinary caustic soda is a corrosive but uninflammable chemical substance, but there exist commercial varieties which are extremely dangerous, and which have been noted in the Colony this year.
Such caustic soda contains a proportion of the metal sodium, and bursts into flame on being wetted with a few drops of water. The flame is roughly pro- portional to the amount of water touching the soda.
This caustic soda is externally similar to the pure material in common use, being packed in the same type of drums, which are normally corroded and rather battered. In appearance it is light gray to dark gray or even black, whereas the pure solid is white.
Of all the caustic soda in godown No. 5, only eight drums of this inflam- mable soda were found. These are all in stack No. 29, and their position is shewn in the enlarged plan of this stack (Plan No. 2).
All these eight drums when examined were intact, and shewed no signs of the foaming, spattering or bursting, that would have occurred had water accidentally dropped on to their contents.
It will be noted that two empty drums were found on this stack, as shewn in Plan No. 2. At one time it was thought that some of the soda was in the process of being repacked into one or other of these drums. It might thus have stood open all night, and become inflamed through a water drip from the courtyard above, thus setting alight to the lacquer stack No. 40 adjacent. This theory was disproved by the absence of any trace of caustic soda on either of the drums.
In spite of the presence of this dangerous material, therefore, it appears unlikely that the fire originated therein.
6. FINAL THEORY OF ORIGIN, PROPERTIES OF NITRATE FILM.
This brings us to the last theory formed; that of the cause of the fire being self-ignition, or spontaneous combustion, of the washed film.