I was oblized to tell a short story about recent american sign practice: exposed lamp signs, neon signs and sign maintenance which I saw and heard my self in America last year. This is the shorthand record of it.

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In this report the author proposes a method for the investigation of the qualities of heatingwires, which is derived from his experiments as reported in previous papers as well as from a chemical analysis which is contained in the present paper.
The experiments, conducted in Japan on several heating-wires of both foreign and domestic markets, are concerned with the following subjects:
(1) Electric resistance and temperature,
(2) Thermal expansion coefficient,
(3) Tensile strength at various temperatures,
(4) Oxidation at high temperature,
(5) Life at high temperature,
(6) Current-temperature relation at various coil pitches.
(7) Analysis of chemical composition from these experiments he tried to find:
(i) The comparative qualities of Japanese wires and foreign wires,
(ii) Design constants,
(iii) Facts affecting the life of the wires, especially the relation among the life, oxida tion and amount of iron content,
(iv) The bestimethod of quality-determination.
The first two, (i) and (ii), have already been reported, and the present paper treats with the last two, (iii) and (iv)
The dimensional irregularity of a wire, the amount of oxidation and some other unknown facts, like chemical heterogeneity, are supposed to affect the life of a wire.
The effect of oxidation is divided into two components, one effect from the uniform oxidation during continuous heating and the other effect from the oxidation at the beginning of preheating after a period of cooling. Therefore, a number of repeated heatings should he considered in deter mining the life as well as the total heating time.
But the amount of oxidation, except in extreme cases, as in Chromel C, fails to estimate the life, because it gives only the average amount of oxid ation and nothing of the special oxidation at some particular weak point of a wire, which seems a more important factor since it causes a hot spot.
On the contrary, the change of resistance in such stages shows the total effect resulting from every kind of cause, and not from oxidation only, since the measurement of resistance in open air gives a much more adequate result for determination of life.
The slope of a resistance-time curve at a given temperature and the change of resistance by a number of repeated heatings can determine the life of a wire at that temperature, not taking into cosideration the effect of hot spots.
The resistance-temperature curve taken in the open air gives the actual value of resistance for design, and the temperature-coefficient of resis tance obtained from this curve contributes to distinguish the wire for low temperature use from that for high temperature use.
A very large percentage of iron caused great oxidation, but the author could not find any definite result with a moderate percentage of iron, and also any reason why the iron content of wire for high temperature use should be less than one percent.
The life of wire which contained a higher percent of silicon seemed to be greater.

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