A new formula of the vertical distribution of wind velocity presented recently by Deacon
u =((az₀^1-β)/(1-β)){(z/z₀)^1-β-1}
where u denotes the wind velocity at the height z and a and β are constants, represents well many experimental results. But there seems to remain something to be examined. The author points out that the roughness parameter z₀ should vary according to the stability of the air layer, whereas Deacon considers this to be constants, and the form of a adopted by him,
a=(υ∗/k) z₀^β-1 ,
where, k=0.4, and υ∗ denotes the frictional velocity, is not correct.

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I classified the fires according to their origins, as A, B, C, D and E. Class A consists of fires originating from small heat origin, for example, cigarette stubs. class B, from a middle and large heat origin, for example, flame, class C, from out-door electric wires which are connected to houses, class D, from spontaneous combustion of chemicals, class E, from the ignition of fats and oils or celluloid.
According to my statistical investigation of fires in Tokyo from 1947 to 1950, fires which belong to class A and C are apt to break out on dry and gusty days, but class D, on hot days. Class B and E have hardly any effect on humidity or wind velocity. On cold days fires originating from B class are frequent because in most homes fire is used frequently for heating.

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When a couple of electric currents flows in opposite direction in a pair of windings of a relay having two pairs, the magnetomotive force due to electric current flowing in those windings will be balanced, and in result the relay does not operate.
But, when one of the electric currents flowing into each winding will be stopped because of the fault of outside circuit, the balance mentioned above will be broken and the relay will be operated.
When four fire detector circuits are connected to each winding to maintain balance in ordinary case, a breaking of the wiring to fire detectors will be indicated directly by the operation of the relay, as soon as it arises.
In such way we can supervise four circuits by means of a relay. In this report the design of a receiving board of fire alarm device with such a new method of supervision is detailed.

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The inclination of the fire flame by wind is an important factor for the spread of fire.
Theoretical investigation showed that the axis of the fire flame inclines as a straight line so far as the flame has constant temperature, and the horizontal inclination θ is given by the following formula,
tanθ=(k(1-p)D)/υ_ω²
Where p…ratio of absolute temperatures of the air and the flame. If the temperature of the flame is supposed as 1000°C, 1-p=0.772.
D…the length of the burning house as measured in the direction of the wind [m].
υ_ω…the velocity of the wind [m/s]
k…a constant.
Then piles of wood of about 1m³ was burnt under various velocities of artificial wind.
This experiment showed the inclination of the axis of the flame is a straight line for the main part of the flame. By this results the constant of the formula was determined, and it was 5.15.
∴ if 1-p=0.772,  k(1-p)≒4
Therefore the above formula becomes,
tanθ=4D/υ_ω²
Further records of actual fire tests which were tested by the object of determining the fire temperature of wooden houses were investigated for the problem of this paper.
This result showed also the correctness of the formula.

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We have developed a kinetic theory of heterogeneous reaction for the purpose of analysing combustion velocity of solids.
By this theory, generalized reaction rate is given as follow :
dz/dt = (S_o/Q) Φ(z) (KΔμ)/((1/k)+(1/γD ∫^II _I dx))
   here, S_o :   initial surface area,
    Q :   initial mass,
    Φ(z)  :   shape function,
    K,γ :   a constant,
    D :   diffusion constant,
     k :   velocity constant in reaction,
     Δμ :   chemical potential,
  ∫^II _I dx :   thickness of diffusion layer,
So we can obtain the required equation by substituting Φ(Z) and proper conditions for this formula.

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In the 5th F. R. I.′s Fire Experiment, I have taken measurements with thermopiles of the effect of the shielding protection by a formal shaped tree from the radiation of wooden houses fire.
One of the aims of this measurements was to check the accuracy of the estimation formula submitted by the writer of the above effect (The Bulletin of the Fire Prevention Society of Japan. Vol. 1. No. 1. 1951), using the solid angle projection method.
In the comparison of the estimation with the measurement it was revealed that
i) the error due to the dealing of the shape of trees as globes will be small, as far as they are formally conical,
ii) but the dealing of shapes and sizes of the heat sources will affect vitally the accuracy of the estimation.

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There have been no data at present which analytically checked water used for the extinction of fire by fire men.
So the volume of the water must be acquired in order to rationalise the extinction of fire by water. In this report the relations between the volume of the water obtained from the investigation of fires by Tokyo Fire Board and the destroyed area, the building structure, temperature, humidity, wind direction and velocity, the cause of breakout of fire, the extent of fire until water is poured and so on are analytically checked by the graphs. The fires adopted to this investigation amount to 347 in January, April and August 1949, December 1950 and March 1951.

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In the buffing shop of plating industry, the dust of buffing materials goes up into the air and accumulates on some beams or shelves. Those accumulated buffing dust has the possibility to be ignited by the sparks produced by buffing operation. We have the report that in a certain buffing shop, two fires successively broke out due to the accumulated buffing dust up on the ceiling beams being ignited by the sparks from a paper-buffing grinder.
The following test regarding the possibility of the ignition of buffing dust was made at the above shop.
The result of the test is as follows :
the buffing dust, which is produced by rubbing of buffing wheels and is in the same form as cotton dust, will be ignited easily by sparks from the operation of buffing grinder. And once it starts burning, its combustion will spread among all accumulations, as amoeba spread their limb, at the average speed of 0.7cm per minute, the maximum speed being 1.0cm per minute. Therefore it is assumed that there is not a little fire hazard latent in such buffing shop.

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We must be know the flashing and burning temperature of chemicals that the woods and other architectural materials of cellulose fibers were treated by chemicals for the purpose of fire-proof.
In this experiment the author adopted the filter-paper treated by chemicals as the test pieces of pure cellulose and considered the burning mechanisms by measuring the flashing and burning temperature of these test pieces.
The results are as follows :
(1) The relation between flashing point and velocity of the fire spreads.
 (i) Alkali salts are go down the flashing point and ammonium salts are raise on flashing point by conc. solution.
 (ii) Fe and Cu salts as FeSO₄ · 7H₂O, CuSO₄ · 5H₂O, FeCl₂ · 4HO, and oxidizing agents as KNO₃, KClO₃, K₂Cr₂O₇ are go down the flashing point.
(2) The relation between burning point and velocity of combustion.
 (i) Ammonium salts are raise on burning point by conc. solution alike (1), but alkali salts are raise on flashing Point by conc.
solution in opposition (1).
 (ii) Fe and Cu salts are low alike (1).
(3) The relation between chemicals and mechanisms of combustion.
 Even if the test pieces are fire-proof treated by chemicals are burning up in about 600°C when to have a good supply of air and so the only one preventing method of burning is make an imperfect surface combustion.
(4) The relation to fire.
 When the architectural materials are acted upon by alkali, are go down the flashing point.

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