MECHANICAL APPLIANCES.

To Raise and Move a Heavy Body.--On Land.--Lever up its ends alternately,

and build underneath them when they are lifted up. After a sufficient

height has been gained, build a sloping causeway down to the place to

which the mass has to be moved, and along which it may be dragged, with

the assistance of rollers and grease. If the mass be too awkwardly shaped

to admit of this, burrow below it; pass poles underneath it, and raise

the ends of the poles alternately. Mr. Williams, the well-known

missionary of the South Sea Islands, relates how his schooner of from

seventy to eighty tons had been driven by a violent hurricane and rising

of the sea, on one of the islands near which she was anchored, and was

lodged several hundred yards inland; and thus describes how he got her

back:--"The method by which we contrived to raise the vessel was

exceedingly simple, and by it we were enabled to accomplish the task with

great ease. Long levers were passed under her keel, with the fulcrum so

fixed as to give them an elevation of about forty-five degrees. The ends

of these were then fastened together with several cross-beams, upon which

a quantity of stones were placed; the weight of which gradually elevated

one end of the vessel, until the levers reached the ground. Propping up

the bow thus raised, we shifted our levers to the stern, which was in

like manner elevated; and, by repeating this process three or four times,

we lifted her in one day entirely out of the hole (which she had worked

for herself, and which was about four feet deep). The bog that lay

between her and the sea was then filled up with stones, logs of wood were

laid across it, rollers were placed under the vessel, the chain cable

passed round her; and, by the united strength of about 2000 people, she

was compelled to take a short voyage upon the land, before she floated in

her pride on the sea."

In some cases, the body of a cart may be taken down, and deep ruts having

been dug on each side of the mass, the vehicle can be backed, till the

axletree comes across it; then, after lashing and making fast, the sand

can be shovelled from below the mass, which will hang suspended from the

axletree, and may be carted away. Or a sledge may be built beneath the

mass by burrowing below it and thrusting the poles beneath it. Then the

remainder of the intervening sand can be shovelled away, and the mass,

now resting directly upon the sledge, can be dragged away by a team of

cattle.

A sarcophagus of immense weight was raised from out of a deep recess into

which it had been fitted pretty closely, at the end of a long narrow

gallery in an Egyptian tomb, where there was no room for the application

of tackle or other machinery, by the simple expedient of slightly

disturbing it in its place and sifting sand into the narrow interval

between its sides and the recess. This process was repeated continually:

the sand settled below the bottom of the sarcophagus, which gradually

rose out of the hole in which it had lain. The principle of this piece of

engineering was borrowed, I suppose, from observing that whenever a mass

of sand and stones is shaken together, the stones invariably rise out of

the sand, the biggest of them always forming the highest layer.

Expansive Power of Wetted Seeds.--Admiral Sir E. Belcher read a curious

paper before the British Association in 1866, showing the remarkable

power to be obtained by filling tubes with peas or other seed, allowing

the weight to rest upon the surface of the peas through the medium of a

rude piston. When the peas were wetted they swelled upwards with

considerable force. A pint of peas placed in a tube of a diameter that

was not expressed in the newspaper report, from which I take this

account, lifted 60 lbs. through a height of one inch in twenty-four

hours. The Admiral proposed to fix a number of tubes side by side in a

frame below the mass to be lifted, preferring to use zinc tubes of from

two or three inches in diameter, and of about one foot high. Thus, in the

small 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.

"Although from its bulk several men might be puzzled to lift a cow-fish

from the water when dead, yet one single Indian will stow the largest in

his montaria without assistance. The boat is sunk under the body, and

rising, the difficult feat is accomplished." (Edwards' 'Amazon.')

The huge blocks of marble quarried at Carrara are shipped in the small

vessels of the country, as follows:--at low water the vessel is buried

bodily in the sand, and a temporary railway laid down from the quarry to

withinside of it. Along this the blocks are conveyed, and, when deposited

in the vessel, the sand is dug away from under them, and they settle down

in its hold, and the ship floats away at the returning tide.

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