Twenty timber species were investigated for the determination of steam bending properties. Presteamed solid wood could satisfactorily be bent by using a suitable hand bending device. A 30 minutes’ steaming period was found adequate to bend 1.27 cm thick wood to a reasonable degree. Sharp bends could conveniently be made in wood of very hard nature at 60 minutes’ steaming. The timber species under investigation were classified into three categories based on their bending properties

Preliminary investigations were carried out for the determination of clay mineralogy of the Sundarban soils. A total of 50 pedons were examined over a north-west to south-east transect running through the Sundarbans. Finally, four pedons were selected for laboratory investigation.
Based on the observations made from the field investigations, as well as from the results of the physicochemical analyses, it appeared that pedologically the soils were very young and possessed no diagnostic horizon.
The dominant minerals in the clay fraction are weathered mica and smectite with traces of kaolinite, chlorite and interstratified minerals. The clay minerals were identified mainly by the X-ray diffraction technique supported by other techniques. It was observed that, so far as the clay mineralogical composition was concerned,the Sundarban soils had a homogeneity both in vertical and in horizontal directions. Slight variation in the clay mineralogical composition and content occurring among the pedons are the inherited properties of the soil materials.

Teak (Tectona grandis) pressure treated with an oil-borne preservative was investigated to find its usefulness as transmission poles. The pole size round Teak was found to contain an average of 45 percent sapwood which is readily perishable by wood destroying organisms. Teak poles were treated by the Bethel full-cell process using varying pressure and duration to evaluate their effect on the penetration and retention ofthe preservative mixture of 40 : 60 creosotelight diesel oil. With the increase of both treating pressure and time the increase in penetration was not found to be statistically significant. The retention, however, significantly increased with the increase of pressure but the increase of time could not produce any significant effect.

A penetration of 1.57 cm with retention of 174.64 kg/m³ of treated sapwood could be obtained by using 8.81 kg/cm² pressure for 3 hours. This penetration is considered adequate to protect the sapwood region of the pole.

Bangladesh is blessed with 119 species of mammals (Khan 1982). The abundance of such a large number of species in a small territory has been possible because of a diversified flora, a characteristic of tropical forests. However, the existing mammalian population indicates a distinctly
deteriorating trend during the past several decades. No systematic survey of mammals has ever been carried out for the area now under the territories of Bangladesh. It is, therefore, difficult to quantify the magnitude of loss. Our knowledge is limited to some old records made by Blanford (1888) and Pocock 1939, 1941) and some recent works (Choudhury 1969, Mountfort 1969, Husain 1974, Khan 1982). None of these records is complete and uptodate and, therefore, further studies are needed in this direction. A reconnaissance survey was made during 1978 and 1979 to assess the status and distribution of some mammals of Bangladesh. This paper discussess the status and distribution of 21species covering 8 families.

An experiment was conducted to find the suitability of 28 miscellaneous hardwood species in mixtures for the manufacture of particleboard. The species were grouped into five specific gravity classes in increasing order based on the specific gravity of individual species.

The average density of the boards of Specific Gravity Class I (667 kg/m³) made from low specific gravity species is less than that of the boards of Specific Gravity Class V (705 kg/m ) made from medium and high specific gravity species but the strength ofthe former (178 kg/cm²) was observed to be higher than the latter (107 kg/cm²). The average strength of the boards of Specific Gravity Class V does not satisfy the ‘standard’ for medium density boards. Species of high specific gravity may be used in the manufacture of medium density board by mixing the chips oflow specific gravity specjes. The thickness swelling (22-35 %) of the boards of all groups was observed much higher than the optimum. This may be reduced by increasing the amount of solid content of UF glue and adding water repellent in the chips during the manufacture of boards.

Teak (Tectona grandis Linn, f.) has occupied a dominant position in the plantation programme ofthe Forest Department in Bangladesh. It is important to know the social rate of return from Teak plantation in order to evaluate the economic suitability of plantation programme and compare Teak with other promising species.

The paper contains discussions on regression of size variation of Teak logs on price changes. Government revenue is calculated assuming that the lot purchasers and the consumers have similar size preferences. Internal rate of return from Teak plantations belonging to site index 15, 20, 25, 30 and 40 is estimated.