Houses built on trees were rare at the time of my stay among the Manóbos of the Agúsan Valley. In the few cases which I saw, the tree was cut off at a point about 2 meters above the divergence of the main branches from the trunk. Then the house was built in the ordinary way by erecting long auxiliary posts, the trunk of the tree and its main branches forming the principal support. In Baglásan, upper Sálug River, I saw a Debabáon house, belonging to Bagáni pinamailan Lantayúna, built on a tree but without any auxiliary posts.
No nails, and pegs only very occasionally are employed in fastening together the various parts of the structure. Either rattan strips or pieces of a peculiar vine5 are used in lashing the beams and crosspieces to the posts, whereas for the other fastenings, rattan strips are universally employed.
5Hag-nái-a (Stenochlena spp.).
THE FLOOR
The floor consists of laths of bamboo, or of a variety of palm6 laid parallel and running along the length of the house with more or less regular interstices. Almost universally one or both sides of the floor, for a width of 50 centimeters to 1.5 meters, are raised to a height varying from 10 to 50 centimeters above the main floor. This raised portion serves for a sleeping place, but in the poorer classes of houses the height of this platform is so slight that I think that there exists or has existed some superstitious belief connected with it, though I have been unable to elicit any positive information on the point. In houses of the better class one occasionally finds roughhewn boards used for the floor of these platforms, as also for the walls.
6A-ná-nau. Palma brava. (Livistonia sp.).
THE ROOF AND THE THATCH
The roof is of the gable style, but is four-sided, with two smoke vents, as may be seen in Plates 4b and 6a. The four beams that form the main support for the rafters are lashed to the posts of the house at a height varying from 1.5 meters to 2 meters above the floor. Four substantial rafters, resting upon the four beams just mentioned, run up at an angle of 45° from the corner posts. Upon these rafters rests the ridgepole. Numerous light rafters of wood or of bamboo extend from the ridgepole in parallel rows at intervals of 30 to 40 centimeters. They project about 50 centimeters beyond the side beams upon which they rest and serve to support the roofing material.