space of a cubic foot, a large number of tubes (thirty-six in the one case, sixteen in the other) could be made to act simultaneously; the force of the stroke could be increased by arranging a number of frames side by side, or the length of the stroke could be increased by building the frames in a series one above the other.  I have elsewhere described how wetted seeds may be used to restore the shape of a battered flask either for holding water or gunpowder (pp. 230).

Parbuckling.—­A round log or a barrel should be rolled, not dragged; and many irregularly-shaped objects may have bundles of faggots lashed round them, by which they become barrel-shaped and fit to be rolled.  In these cases, parbuckling doubles the ease of rolling them; one or more ropes have one of each of their ends made fast in the direction to which the log has to be rolled, while the other is carried underneath the log, round it, and back again.  By pulling at these free ends, the log will be rolled on.  An equivalent plan, and in some cases a more practicable one, is to make fast one end of the rope to the log itself; then, winding the rope two or three times round it, like cotton on a reel, to haul at the free end as before.  Horses can be used, as well as men, for this work.

[Sketch of man pulling log].

Accumulation of Efforts.—­South American Indians are said to avail themselves of their forest trees, and of the creepers which stretch from branch to branch, in moving very heavy weights, as in lifting a log of timber up on a stage to be sawn, in the following ingenious manner.  The labourer gets hold of one of these creepers that runs from the top boughs of a tree in the direction in which he wants to move his log, and pulling this creeper home with all his force, bending down the bough, he attaches it to the log; then he goes to another creeper and does the same with that; and so on until he has accumulated strain of many bent boughs, urging the log forward and of sufficient power to move it.

Short cords of india-rubber with a hook at either end, are sold under the name of “accumulators.”  It is proposed that each of these should be stretched and hooked by one of its ends to a fixed ring, and by the other, to the body to be moved; by applying a number of these, in succession, an immense accumulation of force can be obtained.

Levers.—­A piece of green wood has insufficient strength to be used as a crowbar; it must first be seasoned. (See “Green Wood, to season.”)

Other Means of Raising Weights.—­I do not propose to take space by describing jacks, ordinary pulleys, differential pulleys, Chinese windlasses, and the like.  It is sufficient that I should recall them by name to the traveller’s recollection; for if he has access to any of these things he is probably either a sailor or engineer and knows all about them, or he is in a land where mechanical appliances are understood.

To raise Weights out of Water.—­If the mass should lie below water, a boat may be brought over it and sunk to its gunwales; then, after making fast to it, the boat can be baled and the thing floated away.  A raft weighted with stones will serve the same purpose.  In some cases a raft may be built round the mass during low water; then the returning tide or the next flush of the stream will float it away.