Iron sand of low phosphorus and high vanadium contents, produced in Nimai-bashi, Ohata-machi, Shimokita-gun, Awomori-ken, was taken as the original material. When. this material was refined by the direct steel-manufacturing processusing an electric arc furnace, the cost of curent for removing phosphorus was dispensed with, as it was unnecessary to do so. Further, the material having been high-vanadium iron sand, ordinary cheap carbon steel was not produced, but vanadium in iron sand was reduced and entered to the steel, so that high-grade vanadium steel was economically manufactured.

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The transformation velocity of steel changes according to its composition and maximum heating temperature. The present work was undertaken to determine the transformation velocities of 27 nickel-chromium steels containing different quantity of nickel, chromium and carbon by dilatometric measurement, since the velocity is of practical importance in the heat treatment of steel. Each specimen was cooled with different velocities, and the relation between the cooling velocity and the amounts of the normal (Ar') and lowered (Ar") transformations was plotted, from which the critical cooling velocity, i.e. the minimum velocity which the Ar' transformation to be completed, or the Ar" transformation begins to appear as the cooling rate further increases, was determined.
It is found that as the maximum heating temperature rises, the transformation velocity of the Ar' change is delayed, and as the carbon content increases up to a certain amount (0·2-0·3%) the velocity of the Ar' change is delayed and then hastened with further addition of carbon, and also that as the nickel or chromium content increases the transformation velocity is retarded; the effect is larger by chromium than by nickel. In series of specimens with 1·7% Ni, 0·85% Ct and 3·2% Ni, 0·85% Cr (with both different in carbon contont) the transformation velocity is fairly rapid, while in those with. 4·7% Ni, 1·7% Cr the velocity is very slow, requiring 4-8 hours in cooling through the range 700 to 500°C from 850°C for completion of the Ar' change. The microstructure of specimens used in the dilatometric measurement was also examined, and the relation between the structure and the transformat on point in the dilatometric cooling curve was clarifieed.

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Five years ago, the author described, in this journal, on the thermal conductivity of numerous kinds of cast iron.
In this paper, he reports the results of the thermal conductivity of some kinds of special steel measured with the same apparatus as that was described in his previous reports. The temperature range experienced extends over ordinary temperature up to about 800°C, and the kind of steel is as follows:-
(1) Carbon steel: 2 kinds, (2) Nickel chromium steel: 3 kinds. (3) Stainless Steel:
2 kinds (4) High speed steel: 2 kinds.
As it is known that the thermal coductivity of cast iron or steel is affected by the microscopic structure more than the chemical composition, he measured the thermal conductivity of each steel in quenched and tempered conditions in addition to annealed condition.

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The so-called "Sump Method" is a new device of making microscopic prints by means of placing a thin celluloid film with solvent on the surface of the specimen and removing it thus to reveal the structure of material. Hence, it is unnecessary to cut out the specimen from the body of material as is done in the case of ordinary microscopic preparation.
In the present paper the author intends to describe the way of its practical application and the efficatious operating method for the investigation of the structure of metals and alloys under the following headings.
1. Introduction.
2. The "Sump Method" and its way of manipulation.
3. Etching of the specimen.
4. "Sump" printing of the structure of metal.
5. Microphotography of the "Sump" preparation.
6. Polishing of the metal and its necessary apparatus.
7. Conclusion.

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The 19^th Sectional Committe of the Japan Society for The Promation of Scientific Research has made investigation on the methods for analysing gases in iron and steel since its foundation and has endeavoured to standardize such methods and devices. Previously the device for the analysis of nitrogen was completed and recently patented, and its method was published in Report No. 1 of the 19^th Committee and is now commonly adopted in various places in this countoy.
The analysis for oxygen may be classified in to three processes, viz., (1) residual process, (2) hydrogen reducing process, and (3) vacuum melting process. In future, the Committee is going to make investigation on the three processes, and at first the hydrogen reducing process has been deald with. On this process, the original scheme was proposed by Mr. Keijiro Kurokawa, and the method of taking specimens, the device and process were examined in the committee meetings which were opened several times. The same specimens extending over various kinds were specially made and sent to various places in order to receive the results of analysis by the proposed method. Finally, it was confirmed, that all the results are in good conformity. The author is pleased to publish the method herein, which is the result of the investigation continued for some four years.

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The authers investigated the mechanical and chemical properties of some temperhardenable Nickel-Bronzes, v.z., No. 1 (Ishikawa Metal), No. 3 and No.4.
The last-mentioned was invented by the present authors, as one of the results of study on Cu-Ni-Fe-Al alloy-series (10-25% Ni, Fe <20%, Al<7%, Cu balance) The Nickel-Bronze No.4. combines great strength and hardness with high corrosion resistance, its properties being as follows.
(1) nominal composition of Nickel-Bronze No.4
Ni% Fe% Ai% Zn% others%
10 10 4·5 <2 <1
(2) Properties of Nickel Bronze No.4 Rods
specific gravity 8·26 (20°C)
coefficient of thermal 19·0×10-6(20-500°C)
expansion
electric conductivity 9·4%(Cu=100%)
yield point (0·2%) 58-75kg/mmmm²
tensile strength 80-95kg/mmmm²
elongation (50mm) 17-20%
Brinell hardness number 210-250
heat treatment tempering at ca. 550°C after
quenching at 900-950°C or
hot -working.
For comparison, some specimens of Kunial Copper and Brass (I.C.I., England), and K-Monel Metal (International Nickel Co., U.S.A.), were examined, and then some hardenable Nickel-Tin bronzes touched upon.

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