Radiation from Burning Houses in the Fire experimentally carried out in Hukoka

[摘要] Wooden houses were experimentally burned in the city of Hukuoka on 14 Oct. 1939, and on that occasion the radiation from them was measured with an instrument specially designed for long wave radiations. As shown in Fig. 1, A and B are thermometers of the same construction, sensitive parts of the former being blackened by the smoke of camphor. The A-thermometer is exposed to the radiator, whose intensity of radiation is to be measured, through a cylindrical tube a, and the B-thermometer is wrapped in a brass cylinderb, the inside of. which is covered with a layer of asbestos, for the purpose of being protected from all kinds of radiation coming into its sensitive parts.To be able to neglect the effect of change of air temperature and to simplify the principle of this instrument, currents of air are sended through the sensitive parts of the thermometers, as constantly as possible, from holes in the lower ends of b and c to those in the upper ends of them.The constant of this instrument, necessary to calculate the intensity of radiation by means of the temperature difference between the two thermometers, was determined by observing the solar radiation with this and a silver-disc pyrheliometer at the same time.The results of observations are shown in Fig. 6 and Table 1. These results enabled us to estimate the maximum temperature of a part of wail, toward which the tube of this apparatus was pointed, and which would be about the center of front wall. It was 895°C at the first fire, when a one-storied house was burned, 1081°C at the second fire, when a two-storied house built as a common type of Japanese residence was burned, and 808°C at the third, when a two-storied house specially built as to be protected from fire was burned.The proportions of the amounts of heat energy emitted by the process of radiation only to the total amounts of heat sended out from the houses are perhaps 17% to 31% at the first fire, 22% to 34% at the second, and 19% to 25% at the third.It is shown that these results of our observation are probable, comparing the calculated values with those obtained formerly by other authors.

[学科分类] 大气科学