In fact, between the mean and the higher level the height of the Amazon could vary as much as forty feet, and between the mean and the lower level as much as thirty feet.

A difference of seventy feet like this gave the fazender all he required.
The building was commenced without delay.

Along the huge bank the trunks were got into place according to their sizes and floating power, which of course had to be taken into account, as among these thick and heavy woods there were many whose specific gravity was but little below that of water.
The first layer was entirely composed of trunks laid side by side.
A little interval had to be left between them, and they were bound together by transverse beams, which assured the solidity of the whole.
_"Piacaba"_ ropes strapped them together as firmly as any chain cables could have done.

This material, which consists of the ramicles of a certain palm-tree growing very abundantly on the river banks, is in universal use in the district.

Piacaba floats, resists immersion, and is cheaply made--very good reasons for causing it to be valuable, and making it even an article of commerce with the Old World.
Above this double row of trunks and beams were disposed the joists and planks which formed the floor of the jangada, and rose about thirty inches above the load water-line.