The basic experiments on segregation have been conducted in order to substantiate the theoretical mechanism of the shape of segregation curves.
  Succeeding to the previous report, almost similar experiment was conducted this time; i. e., by controlling the solidification process of the samples completely and four kinds of samples solidified at the different travelling rates of solidification were prepared, and segregation in these samples were determined.
  The experiments were carried on three cases; i. e., (1) the full length of samples was varied, (2) the cross sectional area of sample was diminished gradually along the direction of solidification, (3) the travelling rate of solidification of sample was increased during solidification.
The gists of the results are as follows:
 (1) When the size of castings reduced, the fiat portion of the segregation curve corresponding to the intermediate layer of castings reduced, and when the size was reduced moreover, the degree of segregation decreased.
 (2) Regarding to the shape of castings, it was clarified that the segregation in cylindrical castings became to a high degree than the segregation in fiat castings.
 (3) When the travelling rate of solidification increased during solidification, the degree of normal segregation in castings became markedly.

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  This study is carried on with the purpose to know the influences of the kinds of silica sands, the additional amounts of synthetic resins and wetting agents on the temperature and the times of setting and curing the shell molds and on the bending strength and the thickness thereof.
  The gists of the study are as follows:
 (1) With a conical silica sand of larger grain size, thickness and bending strength of the shell becomes greater than those of a bank sand of finer grain size.
 (2) When the additional percentage of resin is 10, the thickness of the shell becomes a little thicker than that of 5 or 15 percent of resin is added. But the bending strength is gradually increased with the increasing amount of resin addition. Moreover, both the thickness and the bending strength of shell become greater as the setting temperature, time and the curing temperature become greater.
  Accompanied with this, the color of the shell becomes darker.
 (3) When 0.1 or 0.2 percent of wetting agent is added to the mix of the Utsumi silica sand and the Sp 61 M synthetic resin of 10 percent, the bending strength becomes greater than that of the mix without wetting agent addition.

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  We have been investigating the geological origin, crystal structure, hot properties and refractoriness of 4 foundry silica sands in Tōkai district; Mikawa Synthetic Silica Sand, Seto Conical Silica Sand, Seto Natural Silica Sand and Chita Beach Sand.
  Now we report the result investigated by crashing of these silica sands at room temperature. Crashing method is the shock-crashing by ramming. The grain sizes of these sands are 35, 48, 65, 100 and 150 mesh.
  The gists of the experiments are as follows:
 1. The crashing of these silica sands at grain size and kind has each characteristic.
 2. We found that these characteristics are closely connected with the geological origin of each silica sand.
 3. The smaller the grain size of silica sand is, the more the difference of the crashing of these silica sand decreases.
 4. As for Synthetic Silica Sand, Conical Silica Sand and Natural Silica Sand, the bigger the grain size of these is, the more easily they crash.

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  A fundamental research on the inorganic binders produced in Japan was made in this report. The samples used in this experiment belong to the following various kinds of clay produced in Japan.
  Montmorillonite group····Bentonite of Hōjun brand
  Kaolite group····Kibushi clay
  Secondary mica group····Red clay of Haru-machi
  Mixed type····Clay of Mitsuishi
  These clays were submitted to various analyses such as chemical analysis, X-ray analysis, electron microscopic analysis and differential thermal analysis, while their swelling capacity, base exchange capacity, pH. value and others were measured, the result of which was discussed relatively with binding power.
  In the next place, the change in the binding power on heating above 100°C was experimented with the synthetic sand to which four kinds of clays were added, and have taken the following results.
  1) Any clay belonging to each group considerably loses its binding power when it is heated up to the temperature where combined water begins to discharge.
  2) The green strength of the synthetic sand to which the clays heated to various temperatures are added changes as, follows:
  bentonite····The strength lowers in a marked degree by the heating above 600°C, but makes little change up to 500°C.
  The strength of both Kibushi clay of kaolite group and Harumachi clay of the secondary mica group gradually falls off with heating, the former making a sudden drop at 450°C and the latter above 400°C,
  3) The dry strength of the above-mentioned synthetic sand is subject to the effect of specimen drying temperature.
  The synthetic sand, due to the effect of to Bentonite, shows no change in dry strength under the drying temperature less than 400°C, but drops its strength a little at 500°C and considerably at above 600°C.
  In case of the clay belonging to the other group, the strength of it gradually decreased with the rise of drying temperature, showing minimum strength at a certain temperature and at a temperature higher than that, the strength rose again, coming down at above 650°C.
  The drying temperature showing this minimum strength was 350°C with Harumachi-clay, 450°C with Kibushi clay and 450°C with Mitsuishi clay.

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  In order to know the life of the refractory brick in cupola, I have set up various kinds of bricks in cupola and checked how differently they would start to break down. Simultaneous with this investigation, a comparative test has been done to determine endurability of the brick by a special brick life tester.
  This tester will determine the characteristics such as refractoriness, erosion resisting and spalling, etc. of the brick simultaneously and systematically.
  The following results were obtained about the life of the acid cupola brick by these two experiments.
 1) The endurability of the brick for cupola is closely related with its erosion resisting property against slag.
 2) The spalling resisting property of the brick gives considerable effect upon its endurability.
 3) The brick of high refractoriness is not necessarily desired for the cupola brick.
 4) The endurability of the brick is highly dependent upon the heating temperature in the cupola.
 5) Agalmatolite brick, under the proper conditions, has highest endurability as the cupola brick.
 6) The endurability of mortar is much inferior to the brick of same quality.
 7) The result of test by this brick life tester corresponds with endurability of the bricks set up in cupola.

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