It shall be twice recognised that the height of “Modo-matsu” is still keeping the superior position for the ordinary japanese black pine (P- Thunbergü). As the result of the second measurement, it is found that not only the height but the diameter is also larger for “Modo-rnatsu” than for “Kuromatsu.” In addition to above, the relative Variations of both diameter and height are always smaller for “Modo-matsu” than for “Kuromatsu”, namely, the sizes of single tree are relatively more uniform for “Modo-matsu” than for “Kuromatsu”
Thus, it can be advised that the strand forest of Ibaraki Prefecture, at present, mainly composed of the native japanese black pine (“Kuroiriatsu” P. Thunbergü), shall be improved as the better one for forestry by introducing “Modo-matsu” from the home land “Kiushiu”
Under the present state, concerning to the tree-heinght curve, there is discussion no more. (April, 1948)

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Some Experiments on the Resistance Caused by Snowsledges Used for Tractor-Transportation in Logging.
Makoto Fujibayashi
Seihei Kato
Masakazu Maruyama
Minoru Kamiisaka
Result of some experiments measuring the amounts of resisting forces coused dy snowsledges used for logging, when they were pulled by a tractor, are reported in this article. Resisting forces were measured with a tensionmeter, the coefficients of net running resistanceand these of start resistance calculated, and some factors such as the conditions of snow surface, pullng speed etc., whicn were concidered the values of coefficients, investigated. The experiments were performed on March to give any influenceto 6, 1948, in the National Forest logging place at Takanosu in Akita prefecture. A Mitsubishi T-25 type 3t caterpillartractor and usual woo den sledges loaded with Sugi-logs weighted 3280 to 7760kg and connected with wireropes were used for the purpose.
Analysing the result of the experimets, followings are suggested.
1) Mean values of coefficient of net running resistance varries detween 35-74kg/t when the mean velocity of the sledge shows 5.33-9.47km/hr.
2) Smaller resistance are caused in the case of running on snow surface than in the case of running on soil surface.
3) Resistance increases when running speed increases.
4) Larger resistance occurs on virgine snow surface than on sledge-way of compact snow.
5) Large deviation of the amount of net running resistance obsereved, and the maximum value of which may be decresed when the connecting methods are improved.
6) Resisstance of start (107_??_243kg/t) is 2-3 times larger than the value calculated theoretically, in which the initial velocity of the sledge is assumed to be equal to that of the tractor itself. The necessity of improving to the connecting devices are also suggested.

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Tôichi Miyoshi, Shinji Hirai and Tetsusuke Chiaki: Preparation of the bardened fiber-board with saw-dust and casein. I. On the water-content of the material before press.
Several physical and mechanical properties of the hardened fiber-board prepared with saw-dust and casein were studied when the water-content of the material before press is changed. The quantity of casein was 5% of those of whole materials (saw-dust, casein, Na OH, Ca (OH)₂). The water-content of the material before press was changed from 11% to 31%. Specimens were prepared by hot-press method i.e. the pressure at 100 kg/cm², the temperature at 130°C for 30 minutes. The thickness of specimens was between 0.72cm and 0.82cm. Physical and mechanical tests indicated that the specimen of about 16% of water-content before press has the best quality.

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Toichi Miyoshi, Shiuji Hirai, & Hikaru Okazaki: Preparation of the hardened fiber-board wich saw-dust aud casein, II. On tle condition of pressing and heating. Several physical and mechanical properties of the hardened fiber-boa rd prepared with saw-dust and casein were studied when the temperature, the time and the pressure at the preparation are changed. The preparing method of material was as the same of the preceeding report. The pressing temperature was changed as 00, 130, 160°C, the pressing time as 30, 60 minutes, and the pressure as 50, 100kg/cm² The best quality of the specimens was indicated by the conditition of 130°C. 60 minutes and 100kg/cm²

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Kakuichi Kitahara: On the physical and mechanical properties of hardened fiber-board.
The physical and mechanical properties of a hardened fiber-board with saw-dust and pheneol resine were compared with those of the masonite has advantage over the hardened fiber-board, except the compressive strength and the hardness. The superiority of the masonite will depend upon the peculiar methode of the masonite and the long fiber of jute, consisting a great portion of it.

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It is well known fact that a blood has excellent glueing strength and water proof as a glueing material.
The writer is now carrying out the experiments on the strength and water proof of the glueing materials, and on the relation of the glueing temperatures, times of press, and power of pressure to the glueing strength. As the samples, bloods of horse and ox were used in the experiments. After the blood completely separated to two parts of resum and blood-cake, each of them was dried up respectively. The dried serum was named as “serum glue”, the dried blood-cake as “blood-cake glue”, and the blood powder as “entire blood glue”.
The ply-woods which were made using the three kinds of glue were tasted in the experiments. The tested pieces of the ply-wood were soaked for 4 hours in the hot water with 50°C., and then dried in air for 24 hours. The results obtained from the experiments ars as follows.
The blood-cake and the entire blood glues seem to have a greater glueing. strength than the serum glue.
2. When the ply-wood is made by use of three veneers, each having the thickness of 1.3mm., the following conditions are necessary:-
(a) the time of press: 5 minutes; (b) the temperatnre of glueing: 100°C.;
(c) pressure: 10kg/cm².
3. The glueing materiales made with blood of horses and oxen seem to have a greater strength of water-proof.
4. The water-proof of the glueing materials seems to be increased with addition of the cuprous salt, especially remarked increased in the case used blood-cake glue.

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K. Horioka, T. Murata, T. Midorikawa, On the moulding saw dust.
We have been studied many mouldiug methods, and examined the compressd strength of what have been obtained. The methods and obtained results are shown as follows.
(1) Shaped moulding saw dust by non treated with chemicals.
We shaped moulding saw dust by non treated with chemicals. (moulding condition;- at 160_??_180°C, in 80kg/cm², for 15 mins.)
(2) Shaped moulding saw dust by treated with chemicals.
We shaped moulding saw dust by treated with chemicals as follows. (moulding condition; -at 150°C, in 80kg/cm², for 40 mins.)
I Utilization of lignin in wood.
II Utilization of cellulose and hemicellulose in wood.
III Utilization of pentosan in wood.

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