Abstract
The temperature distributions of air along the ceiling in the early stage of a fire are measured, burning alcohol filled in the flat vessels in a concrete room.
As measuring apparatus of temperature I use 24 Cupper-Constantan thermocouples, recording their electromotive force by magnetic oscillograph.
In experiment A, the horizontal distribution of temperature in the plane 5cm under the ceiling is measured, and at the same time the effects of joists are investigated.
In experiment B, the vertical distributions of temperature in the hot layer directly under the ceiling at three points are measured.
From these experiments the following conclusions are obtained.
( 1 ) The effect of joists on the temperature distribution along the ceiling is almost negligible, but on the time lag of temperature rise amounted to several seconds is recognised.
( 2 ) The layer of hot air separated distinctly from cold air cannot be observed, but the temperature of air near the ceiling rises with time uniformly without changing its profile.
