Explanations are given on the occurrence of the diatomaceous earths deposited in abundance over the Noto peninsula depending on the chemical composition of the samples collected by one of the authors during actual survey and also referring to the published papers on the geology of the concerned districts. The results of the microscopic observation on the diatomaceous earths procuced at the vicinity of Wajima and Wakura, noted as typical places of the occurrence, are reported and their qualities are discussed.

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Die Brenns-Versuche und elektrischen Charakter der japanischer Porzellan-Massen, den seiner alkali-oxyde Bestandteilen beshränkt auf das Gebiet von 0, 007 zu 0, 039 Molekule, die enthalt von 0, 45 zu 3, 48 Moleküle der TiO₂, sind erfolgten.
Uber den Messungs-Methoden für Verlustwinkeln wird diskutiert, ferner, den Messungs-Geräten und den Elektroden sorgfältig erforscht wird.
Die Tan δ wird am tiefsten Wert, wenn den Moleküles-Zahl der TiO₂, 2, 6 sei, hierauf zum der Staatit-Massen ähnelt. Die Dielektrizitätskonstant steigt oder nimmt mit dem Tan δ ab. Der Verfasser zeigt dass die Titan-haltigen-Maassen in der Brenns-Vorgange, vermeiden TiO₂ zu reagieren als basische oxyde von grosze Wichtigkeit ist.

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Two series of magnesite refractories, one fired adequately or insufficiently and another vitrified, have been examined for the ratio of modulus of rupture to modulus of elasticity (R) as well as for spalling tendency (S). A comparatively pure magnesite clinker and an easily vitrifiable one were used. Test pieces were made of bodies of 90 to 0% of coarse grain and 10 to 100% of fine powder. Both coarse grain and fine powder were prepared to have each constant fineness. The batches were wetted with an aqueous solution of magnesium sulphate and were pressed with pressures varying from 2 to 1000kg. per sq. cm.
The following conclusions may be justified by the results of the experiments:
(1) The resistance of magnesite refractories to thermal shock changes quickly on vitrification. Properties of the vitrified refractories are more important than those of unvitrified ones, since the refractories are usually vitrified in service.
(2) If the refractories are not vitrified, the more the amount of the fine powder the more the numerical value of S; S and R decrease with an increase of the forming pressure.
(3) S increases on vitrification. The smaller the amount of the fine powder and the forming pressure the smaller the rate of the increase. The increase is rapid as the amount of the fine powder and the forming pressure increase.
(4) The effects of the amount of the fine powder and the forming pressure for nonvitrified refractories are quite reverse to those for vitrified ones.
(5) With vitrified refractories, the effect of the forming pressure is slight for coarsely grained specimens while spalling tendency of fine grained ones is rapidly reduced by an increase of the forming pressure.
(6) S can be reduced by an adequate increase of the forming pressure and by a decrease of the fine powder or better by pressing weakly batches mainly composed of the fine powder.

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Mixtures of 80 or 100 parts of a pulverized clinker and 20 or 0 pt. of a pulverized calcined magnesite were, on addition of aqueous solutions of dextrin, magnesium chloride, and magnesium sulphate, pressed to test pieces under a pressure of 1000kg. per sq. cm. The test pieces have been examined for compressive strength after 1 week, that on drying, that on heating at temperatures ranging from 100 to 1160°C, and also that on firing to cone 16 with the following results:
(1) Compressive strength of the unburnt specimens has been suddenly reduced with an increase of the content of moisture.
(2) It is likely that the temperature thereat the compressive strength of each specimen is lowest is lowered with a depression of the purity of the clinker.
(3) The temperature has been lowest with dextrin, medium with magnesium chloride, and highest with magnesium sulphate.
(4) The hot minium strength seems to be very low with dextrin, much higher with the chloride, and very high with the sulphate.
(5) The range of temperatures at which the specimens hardened with the sulphate have shown the lowest or like strength has been narrow.
(6) Test pieces which were made of the pulverized clinker and a solution of magnesium sulphate and by pressing with a pressure of 1000kg. per sq. cm. have shown the minimum hot compressive strength of 294kg. per sq. cm. They can probably be used without firing. They have shown linear firing shrinkage of 5% or thereabouts. However the shrinkages will be reduced by half by introducing coarse grain of the clinker up to about 50%.

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I think, on the study of dust collecting or separating problem, it will be required the investigation of motion of fine particle moving in a fluid. In this first article of the series, motion of particle, which is flowing and falling through horizontal steady flow, are methematically treated.
When a particle moving in above flow, motion of particle will be repressented by following equation approximately.
dx/dt=U
4/3πr³ρd²y/dt²=4/3πr³ρg-6πrηdy/dt-4/3πr³σg-2/3πr³σd²y/dt²
dz/dt=0
where r: radius of partclec t: time
ρ: density of particle x, y, z, : properly choosed rectangular coordinate axis
σ: density of fluid
η: viscosity of fluid
U: velocity of fluid
g: gravitational acceleration
If we choose the origin of coordinate axis (their directions are remain as above) to the beginning point of motion, the solution gives as follows
y=(4ρ+2σ)(ρ-σ)/81η²gr⁴(e-9ηx/(2ρ+σ)r²U-1)+2(ρ-σ)yr²x/9ηU
z=B
where B: any constant

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