This paper involves research regarding the processes of introducing steel structure technologies in plant construction within naval dockyards during the Meiji Era. Steel structure technologies introduced at naval dockyards consisted of, first, the cast iron era of the 1890s, and the steel era of the first decade of the 1900s. In regards to the steel era, in tandem with the development of policies for the national production of warships by the Japanese Navy, the introduction at each naval dockyard of the technologies of steelmaking companies of the United States and the United Kingdom clarified the processes whereby steel structure buildings, etc., were constructed.

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本研究の目的は、『東京都下における旧軍用地並に旧軍用地建物調査』から作成したデータベースを用い、30ha以上の大規模旧軍用地と30,000m2以上の延床面積を有する大規模旧軍建物を対象として、1948年当時の使用状況を明らかにすることである。進駐軍が使用していない旧軍用地や旧軍建物も比較的あり、それらは農地として使用されていたほか、主に、学校、住宅、産業用途、研究所として使用されていた。日本側による使用の特徴としては、同一旧軍用地、旧軍建物において、使用用途が混在している場合が多い点、旧軍の学校や研究所は建物用途が継承されていた点が指摘できる。また、未使用の旧軍用地、旧軍建物は限られていた。

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場所・地域の景観を「露頭」として，場所・地域の「地層」たる場所性・地域性を究明する視点から，北九州市の都心部である小倉城とその周辺の場所・地域の意味を検討する。

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戦後,北九州工業地域の国内的地位の低下の実態と要因を明らかにした.
1. 全地域生産額の75%を占める八幡製鉄など臨海部重化学工業の停滞は筑豊炭の重要性の減少,大陸貿易の中止などによって有利性を失っている上に,巨大な固定設備を要するこれらの工業の新規投資が市場条件などにより他地域に行なわれているためである.
2. 三大工業地帯では生産の中心となっている機械工業部門が,当地域では筑豊炭田・八幡製鉄・小倉兵廠などの発展条件を有しながら4部門合せて11%と全く低調である.これは親企業の自己完結的生産体系によって素材加工部門や部品生産のための下請,再下請群などの生産体系が養成されていなかったためである.今日,耐久消費財部門の成長が全くみられないのもここに原因がある.
3. 日用消費財部門が全く欠如している.これは, (1)八幡製鉄の消費財充足形態が成立の事情などから地元に消費財部門を養成しなかったこと, (2)八幡製鉄が諸雑作業のために,日用消費財生産を支えるべき多くの低位労働力を吸収してしまっていること,および, (3)臨海工場によって埠頭が占拠される結果,雑貨取扱を不振とし,ライナーポート化を困難にするため,港依存の雑貨工業の発達が抑圧されたこと,などによるものである.
4. 北九州の停滞はわが国臨海型重化学工業地域の発展の限界を示す最初の事例と考える.

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In a previous paper the author suggested that there are three hardening phenomena in Duralumin alloys, namely:
(1) Primary hardening (Natural age-hardening)
(2) Secondary hardening (Natural age-hardening after “Rückbildung”)
(3) Temper-hardening (Artificial age-hardening)
The primary hardening may be explained by the theory of congregation (or aggregation) of solute atoms at certain selected positions on the Aluminium lattice, and the sudden reduction of the hardness on short period tempering at somewhat higher temperatures (“Rückbildung”, “Retrogression, ” “Intermediate softening” or “De-hardening”) may be attributed to the dispersion of the aggregated solute atoms into solid solution, and the subsequent recovery of hardness at room temperature (The secondary hardening) may be attributed to reaggregation of solute atoms by the quite same process as that occurring in primary hardening. The temper hardening takes place on the basis of precipitation of so-called “intermediate” phase or of compounds, but the maximum hardness generally is attained prior to the appearance of lamellar structure under the microscope.
According to the latest investigations by Preston, the formation of Cu-rich thin platelike aggregates are presumed when the Cu-Al alloy is aged at room temperature and there are diminution of aggregates when “Rückbildung” takes place by short period tempering at 200°, but if the tempering is continued for several hours, the thin platelike aggregates are formed again, The linear dimensions of thin platelike aggregates which were formed at room temperature are far more smaller than that of aggregates which were formed at 200°. (about 40 Å for the former, and about 4000 Å for the latter).
In the present paper the author has made a characteristic differentiation between the natural age hardening and the temper-hardening by the experimental evidence, and deduced the theory of aging.
In the above mentioned explanations there are not any differences in the opinions of the present author and that of other authors to presume the formations of thin platelike aggregates which are vary in dimensions at different temperatures (the one formed at room temperature and has smaller dimensions, the other formed at higher temperature and has larger dimension). But the presentt author suggests the opinion that there are differences not only in the dimensions of the two kinds of aggregates, but also in their coaguration of atoms in the thin platelike regions of these respective cases.
As the coaguration of solute atoms in the thin platelike region which was formed by natural ageing is far more weaker, so the sudden dispersion of the atoms would be expected by short period tempering, and this phenomenon corresponds to the “Rückbildung” The thin Plate which was formed by tempering is also an aggregate of solute-atoms, but it requires an activation energy to bring about aggregation, and the “state of aggregation” is much stable than that of the former
In the above explanation, the author deduced the theory of aging by applying somewhat same idea of adsorption theory, because the movements of solute in the, solid solution (i.e. the congregation and the dispersion etc.) are analogous to the case of adsorption.
The relationship between the two forms of aggregations is similar to that of two forms of adsorption, namely; the van der Waals adsorption (the weaker state of adsorption) and the activated adsorption (the stronger state of adsorption). The van der Waals adsorption takes place at low temperature and removed more or less completely at somewhat higher temperatures. The activated adsorption recommences at still higher temperatures, but in a different form, as the stronger state of adsorption

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It seems to be influential that the process of age-hardening of Al-Cu alloy is associated with the congregation of Cu atoms on the (100) planes of crystal as suggested by Desch (1934) and Preston (1938).
As to the cause of artificial age-hardening of the alloy, there are precipitation theories as suggested by Fink and others, but several authors assume that the phenomenon is associated with the congregation of solute atoms within the solid solution.
The present author investigated the hardening phenomena of Duralumin, Al-Cu alloy, Lautal and Al-Mg₂Si alloy by tempering these aged specimens at various temperatures (180°, 220°, 260° 300° and 350°) for various durations (from 1/1000 to 80 hr.) and measured the hardness and impact value directly after tempering and repeatedly measured subsequent changes in hardness of the specimens with the lapse of time at room temperature.
When naturally aged specimens are tempered at above mentioned temperatures, the first effect is the sudden reduction of the hardness accompanied with the increase of impact value and the decrease of electrical resistance.
On ageing these softened samples at room temperature, they recover the hardness to the same degrees as that of original specimens accompanied with the decrease of impact value and the increase of electrical resistance, and the author called this phenomenon under the name of “secondary hardening” (denoted by II in Figs.).
The phenomenon of sudden reduction o ` hardness on short time tempering may be explained that the congregated solute atoms have gone back into solution before the precipitation of excess solute begins, and the subsequent re covert of hardness is attributed to the re-congregation of solute atoms as the quite same process of natural ageing.
Softening and hardening processes may be repeated several times as indicated in the Fig. 20 by the repetitiozl of short time tempering and natural ageing.
On the prolonged tempering, the increase of hardness is observed as denoted, by III in Figs. and the author called, this hardening under the name of “temper hardening” according to the suggestion of Prof. K. Honda (1939).
With the rise of hardness due to the “temper hardening” boundary precipitations become visible under the microscope, and then the hardness reaches maximum. (III)
On further duration of times of tempering, the hardness gradually decreases and the lamellar structure becomes visible under the microscope.
On more prolonged tempering, it finally loses the regularity- of lamellar structure and alters its form into small spheroidal particles. The lamellar structure seems to be so called “intermediate” phase as indicated by Guinier and his collaborators (1938), but the maximum hardness takes place prior to the appearance of lamellar structure.
The experimental data on age-hardening of Duralumin alloys have led to the following conclusions:
1. There are three hardening phenomena in Duralumin alloys as follows:
(a) Primary hardening (natural age-hardening).
(b) Secondary hardening.
(c) Temper hardening (artificial age-hardening).
2. Primary hardening may be explained by the theory of congregation of solute atoms which are supersaturated by quenching.
3. The mechanism of secondary hardening may be explained by the same theory as that of primary hardening.
4. During the primary and secondary hardening, the reduction of impact value and the rise of electrical resistance are similarly observed.
5. “Temper hardening” occurs on the basis of precipitation of “intermediate” phase or of compounds, but the maximum hardness is attained prior to the appearance of the lamellar structure under the microscope.

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