A report of some experiments on heat ray reflection and transmission of sereral samples of cloths and papers. Electric heating coil was used for heat ray source and measurement was done with thermo-pile.

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The present recommendation is a suggestel recommendation of the factory lighting, presented by the Committee on Factory Lighting. It consists of three chapters and many appendixes.
Both natural and artificial lighting are con-sidered. It is fully discussed how the adequate illumination, both natural and artificial, results in the efficient production generally and well in the welfare of the workers. Many practical solutions are suggested which may be of use for unexperienced designers or architects.

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HOWEVER light distribution of a source of uniform brightness is obtained by calculating the area of its orthogonal projection, as for the general case, it is difficult to do it.
But almost all kinds of sources in practice may be regarded as surfaces of revolution, and for them I have derived the general formula considering that the surface was the locus of the perifery of a horizontal circle moving vertically and therefore its orthogonal projection is the envelope of a family of ellipses which are the orthogonal projection of the circles.
And yet, I am sorry, my formula is cumbersome for practical uses; but the procc ss for deriving it has given a method for drawing the orthogonal projection of the surface, which Ibelieve fairly useful for such works as predeterminations of light distribution, apparent shapes, etc. from only the vertical elevation of any illuni ii ants.
In this wiper, I gave the pi ocess of drawing accompanied by some practical notice.

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It is said the amount of the oxidation of the heating wire is a measure of its life. But author does not find any report written on the relation between them, and has something to doubt if there are other facts which effect to the life or not. This paper is the preliminary report of the experiment to find the relation between the oxidation and the life of the heating wire.
The amount of the oxidation is expressed by the weight increase per unit area of the outer surface of the wire in mg/cm². The weight increase is measured by the deflection method of the thermo-balance invented by Dr. K. Honda. (l)
Samples tested are the same wires which are used in the former tests of the tensile strength (2) and the thermal expansion. (3) After the outer surface of the wire is polished and cleaned made to the coil of a half cm. dia., and put into the porcelain pot which is hanged from one end of the balance arm down into the electric furnace at the constant temp. 1180°C.
The deflection of the balance is read by the telescope and a scale after 5 min. steps for 5 hours. The sensibility of the balance is set to 2.16mm/mg, and the temperature of the furnace is measured by thr Pt-Pt. Rod. thermocouple and a mil ivoltmeter.
From this test it is concluded that.
(1) The oxidation of the heating wire varies with temperature and the time heated, and has the different speed proper to the material, therefore it is of no use to compare the superiority of the heating wire from the value of the oxidation at a special temperature and time of heating.
(2) Nichrome IV and Chromel C have very great values of the oxidation and the rest of the samples have nearly equal value.
(3) TA and TC which are made in our country have the greater oxidation speeds than the other samples. (1928. 6. 20)

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