The resistivity of the quartz-kaolin-feldspar system was determined and the relation between the resistivity and the composition of bodies was discussed.

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Experiments were made on the relation between temperature and modulus of elasticity of magnesite refractories. For this purpose rectangular test pieces, about 1.5cm. thick, 2cm. wide, and 12cm. long, cut from 3 brands of Japanese magnesite brick, that made in Veitzsch, and Radex brick were placed on 2 knife edges with about 10cm. span in the authors' apparatus and were loaded at centre, using such a load for each test piece that caused a definite deflection at 25°C. The results obtatined can be abridged as follows:
(1) The deflection of the Radex brick was largest at 50°C and then decreased rather irregularly and gradually with increasing temperature, while that of other bricks increased markedly at temperatures ranging between 125° and 450°, 300° and 475°, 350° and 450°, or 250° and 425°, was noticeably higher at 450° than at 25°, and morever showed a peak at 625° or 600°. The Radex indicated a small peak at 400°. Then the deflection of every brick decreased greatly at temperatures higher than 400° to 825°, although that of the Radex increased slightly but rapidly at 900° to 950°.
(2) It was observed of a Japanese brick manufactured about 10 years ago that the rate of thermal dissociation rises rapidly at temperatures ranging from 390° to 440°, and also that the increase of the deflection at 300° to 475° disappears on herting it to 950°. Thus it is very provable that magnesite refractories hydrate in atmosphere with formation of hydroxide and basic carbonates of magnesium, causing an increase of elasticity.
(3) The slight but rapid rise of the deflection at about 600° can hardly be explained.
(4) The intense, rapid or gradual decrease of the deflection beginning at 400° to 825° may owe to the formation of a glass phase.
(5) Moduli of elasticity of magnesite refractories at high temperatures are proportionate to those at room temperatures.

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The present paper deals with the study of the lithia-lime-silica glasses, in which the increasing amount of lime is replaced by ironoxide from ferrous oxalate.
The glass melting was carried out with the glover electric furnace in the same way as already dealt with in the Xth report, the amunt of each melt being just 250g of glass.
The results of the total analysis and the percentage ratio of FeO/FeO+Fe₂O₃ are set out in the following table.
It must be noted from the above table that the content of alumina in these glasses is considerably high, owing to the violence of the action of lithia upon the refractory clay pot.
Although the percentage ratio of FeO/FeO+Fe₂O₃ seems to be somewhat irregular, it increases with the increasing amount of ironoxide till 1% of total iron and at the range of over this amount of iron, it keeps almost the constant value in general.
The transmission curves were determined for each sample of 1mm thickness.
Also the total transmissions were determined from the said curves and were compared with those of the glasses FD in the Vth report and FDK in the XIth report respectively.
From the abve table it may be generally said that there are no remarkable distinctions between the total transmission values of the three kinds of glasses at the range of less than 1% of ironoxide and at the range of over this amount there can be found the appreciable distinctions between them and also that the potash glass gives the best, the soda glass the moderate, and the lithia glass the least transmission respectively.
The colour of the lithiumoxide glass varies with the increase of iron content and generally saying, what contains small amount of iron shows the faint bluish colour and with the increase of iron content the glasses of the colour varying from bluish to greenish or even dark bluish black opaque have been obtained.

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1. Gas flow in a cement rotary kiln holds a turbular motion. Maximum velocity of gas at the central axis of the gas column is a little greater at the sintering zone and its arounds, than the rest parts.
At a given kiln, loss of energy due to friction is nearly proportional to the square of its gas velocity.
2. Nearly all raw meal in a rotary kiln, excepting clinker above 117μ dia., is probable to be suspended and blown off by the gas flow, and this tendency is more intense at the calcing gone and the charge end of raw meal to the kiln.

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