Seikan Ishigai argued that the most critical innovation involving boilers was changing their shapes, for example from cylindrical to water-tube boilers. Poor material and processing technology made the development of the water-tube boiler difficult in the 19th century. Ishigai didn't pay enough attention to the material technology of boilers. In the late 1930's, H.W. Dickinson and E.C. Smith wrote a comprehensive history of the stationary and marine steam engine respectively. But they didn't pay proper attention to the relationship between engines and boilers. The author tries to explain the transition from cylindrical to water-tube boilers using steel for marine navigation. The popularization of thermodynamics among engineers and ship-owners stimulated the invention of the high-pressure marine steam engine. In the 1870's, Alexander Carnegie Kirk tried to make a water-tube boiler for the triple expansion engine. But it was too complex to put the water-tube boiler into practical use. Around the same time, William Siemens invented the open hearth steel process. In the 1880's, Kirk adopted cylindrical steel boilers and triple expansion engines. The practical application of the water-tube boilers required the invention of seamless steel tube. Understanding the transition from cylindrical to water-tube boilers alone isn't sufficient to understand the comprehensive history of the steam engine. Material and processing technology played a decisive role in the development of the marine boiler in that period.
In the 13^<th> Scroll "the Zusho (no) ryo (the Documentation Bureau) " in "the Codes of Engi (the Engishiki) " completed in 927 AD, there are four articles concerning the oldest paper technology, i.e., " the annual papermaking article (nenryoshi-jo) ", "the paper flower article (shika-jo) ", "the article of raw materials for paper (shiryo-jo) " and "the article of one day's norms of papermakers in the each process (zoshi-jo) ". These articles described the lists of raw materials, expendables, tools and equipments for papermaking including their quantities, volumes or sizes. This was because the Zusho (no) ryo mentioned the duties of supplying all amounts of paper used in the Imperial Court. In this study with the intention of grasping the papermaking methods in the old days, the description of the articles mentioned above were construed word for word and all the tools and equipments as well as expendables were carefully examined from the view-points of their usage and applications. The manipulation to arrange suitably these tools and equipments as well as expendables with the papermaking process resulted in building up the image of the papermaking ways in the ancient times. On the base of the amounts of raw materials and the paper made thereof, the basis weights of thick colored paper, thin paper-mulberry paper and gampi paper as well as the pulping yield of the bast fibers were calculated, respectively. The bast fibers were found to be cooked with addition of 20-30wt% alkali from ashes with yielding 58%. The paper was made by using an oblong mould in an oblong vessel, which has supposedly stimulated to shake during papermaking and to transfer from Tamezuki to Nagashizuki. In the process of drying wet paper, it was found that the width of drying board was narrower than those of wet papers, which obliged to stick them on the board with folding the edge of the wet paper by aid of a kind of glue. By comparison of the one day's norms of papermaking the reason was made clear why hemp cloth and Sophora flavescens disappeared from the list of raw materials for papermaking. Finally the method of the dyeing paper for paper flowers was clarified.
Minamata disease occurred because inhabitants consumed the polluted seafood. The official confirmation of Minamata disease was in 1956. However, the material cause of that disease was uncertain at that time. The Minamata Food Poisoning Sub-committee, under authority of the Food Hygiene Investigation Committee of the Ministry of Health and Welfare, determined the material cause of Minamata disease to be a certain kind of organic mercury in 1959. The sub-committee was dissolved after their report. The discussion about the investigation of the cause was performed in a conference initiated by the Economic Planning Agency, which was titled "Minamata Disease General Investigation and Research Liaison Council". The Participants were eight scientists; four fishery scientists, two chemists, and only two medical scientists, which implied that only examination of the organic mercury was to be discussion. The conference was held four times from 1960 to 1961. In the first and second conferences, the organic mercury research from a medical perspective progressed in cooperation with fishery sciences. In the third conference, it was reported that UCHIDA Makio, professor of Kumamoto University, had found organic mercury crystal in the shellfish found in Minamata-bay. Authorities of biochemistry and medicine in the third conference criticized UCHIDA's research. At the fourth conference, reports contradicting his research were presented. Although those anti-UCHIDA reports were not verified, AKAHORI Shiro, the highest authority of biochemistry, not only accepted them, but also expressed doubt in the organic mercury causal theory. Therefore, this theory was recognized as uncertain.