CHAP. XIV. Mechanical compared with manual force. 171

cording the memory of great exploits, or in producing feelings of reverence and devotion-it is clearly an advantage that these works, as well as all other works, should be performed in the cheapest manner, that is, that human labour should derive every possible assistance from mechanical aid. We will give an illustration of the differences of the application of mechanical aid in one of the first operations of building, the moving a block of stone. The following statements are the result of actual experiment upon a stone weighing ten hundred and eighty pounds.

To drag this stone along the smoothed floor of the quarry required a force equal to seven hundred and fifty-eight pounds. The same stone dragged over a floor of planks required six hundred and fifty-two pounds. The same stone placed on a platform of wood, and dragged over the same floor of planks, required six hundred and six pounds. When the two surfaces of wood were soaped as they slid over each other, the force required to drag the stone was reduced to one hundred and eighty-two pounds. When the same stone was placed upon rollers three inches in diameter, it required, to put it in motion along the floor of the quarry, a force only of thirty-four pounds; and by the same rollers upon a wooden floor, a force only of twenty-eight pounds. Without any mechanical aid, it would require the force of four or five men to set that stone in motion. With the mechanical aid of two surfaces of wood soaped, the same weight might be moved by one man. With the more perfect mechanical aid of rollers, the same weight might be moved by a very little child.

From these statements it must be evident that the cost of a block of stone very much depends upon the quantity of labour necessary to move it from the quarry to the place where it is wanted to be used. We have seen that with the simplest mechanical aid labour may be reduced sixtyfold. With more perfect mechanical aid, such as that of water-carriage, the labour may be reduced infinitely lower.

Thus, the streets of London are paved with granite from Scotland at a moderate expense.

The cost of timber, which enters so largely into the cost of a house, is in a great degree the cost of transport. In countries where there are great forests, timber-trees are worth nothing where they grow, except there are ready means of transport. In many parts of North America, the great difficulty which the people find is in clearing the land of the timber. The finest trees are not only worthless, but are a positive incumbrance, except when they are growing upon the banks of a great river; in which case the logs are thrown into the water, or formed into rafts, being floated several hundred miles at scarcely any expense. The same stream which carries them to a seaport turns a mill to saw the logs into planks; and when sawn into planks the timber is put on shipboard, and carried to distant countries where timber is wanted. Thus, mechanical aid alone gives a value to the timber, and by so doing employs human labour. The stream that floats the tree, the sawing-mill that cuts it, the ship that carries it across the sea, enable men profitably to employ themselves in working it. Without the stream, the mill, and the ship, those men would have no labour, because none could afford to bring the timber to their own doors.

What an infinite variety of machines, in combination with the human hand, is found in a carpenter's chest of tools! The skilful hand of the workman is the power which sets these machines in motion; just as the wind or the water is the power of a mill, or the elastic force of vapour the power of a steam-engine. When Mr. Boulton, the partner of the great James Watt, waited upon George III. to explain one of the improvements of the steam-engine which they had effected, the king said to him, “What do you sell, Mr. Boulton?" and the honest engineer answered, “What kings, sire, are all fond of-power." There are people at Birmingham who let out power, that is, there are people who have steam-engines who will lend the use of

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CHAP. XIV. Waste of power from imperfect tools. them, by the day or the hour, to persons who require that saving of labour in their various trades; so that a person who wants the strength of a horse, or half a horse, to turn a wheel for grinding, or for setting a lathe in motion, hires a room or part of a room in a mill, and has just as much as he requires. The power of a carpenter is in his hand, and the machines moved by that power are in his chest of tools. Every toil which he possesses has for its object to reduce labour, to save material, and to ensure accuracythe objects of all machines. What a quantity of waste both of time and stuff is saved by his foot rule! and when he chalks a bit of string and stretches it from one end of a plank to the other, to jerk off the chalk from the string, and thus produce an unerring line upon the face of the plank, he makes a little machine which saves him great labour. Every one of his hundreds of tools, capable of application to a vast variety of purposes, is an invention to save labour. Without some tool the carpenter's work could not be done at all by the human hand. A knife would do very laboriously what is done very quickly by a hatchet. The labour of using a hatchet, and the material which it wastes, are saved twenty times over by the saw. But when the more delicate operations of carpentry are required -when the workman uses his planes, his rabbet-planes, his fillisters, his bevels, and his centre-bits--what an infinitely greater quantity of labour is economized, and how beautifully that work is performed, which, without them, would be rough and imperfect! Every boy of mechanical ingenuity has tried with his knife to make a boat; and with a knife only it is the work of weeks. Give him a chisel, and a gouge, and a vice to hold his wood, and the little boat is the work of a day. Let a boy try to make a round wooden box, with a lid, having only his knife, and he must be expert indeed to produce anything that will be neat and serviceable. Give him a lathe and chisels, and he will learn to make a tidy box in half an hour. Nothing but absolute necessity can render it expedient to

use an imperfect tool instead of a perfect. We sometimes see exhibitions of carving, "all done with the common penknife." Professor Willis has truly said, with reference to such weak boasting, "So far from admiring, we should pity the vanity and folly of such a display; and the more, if the work should show a natural aptitude in the workman: for it is certain that, if he has made good work with a bad tool he would have made better with a good one."

The Emperor Maximilian, at the beginning of the sixteenth century, ordered a woodcut to be engraved that should represent the carpentry operations of his time and country. This prince was, no doubt, proud of the advance of Germany in the useful arts. If the President of the United States were thus to record the advance of the republic of which he is the chief, he would show us his

Carpenters and their tools. (From an old German woodcut.)

saw-mills and his planing-mills. The German carpenters, as we see, are reducing a great slab of wood into shape by the saw and the adze. The Americans have planing-mills,

with cutters that make 4000 revolutions, and which plane boards eighteen feet long at the rate of fifty feet per minute; and while the face of the board is planed, it is tongued and grooved at the same time, that is, one board is made to fit closely into another. But the Americans carry machinery much farther into the business of carpentry. Mr. Whitworth tells us that "many works in various towns are occupied exclusively in making doors, window-frames, or staircases, by means of self-acting machinery, such as planing, tenoning, morticing, and jointing machines. They are able to supply builders with various parts of the woodwork required in building at a much cheaper rate than they can produce them in their own workshops without the aid of such machinery."

By the use of those machines we are told that twenty men can make panelled doors at the rate of a hundred a day, that is, one man can make five doors. A panelled door is a very expensive part of an English house; and so are window-frames and staircases. If doors and windows and staircases can be made cheaper, more houses and better houses will be built; and thus more carpenters will be employed in building than if those parts of a house were made by hand. The same principle applies to machines as to tools. If carpenters had not tools to make houses, there would be few houses made; and those that were made would be as rough as the hut of the savage who has no tools. The people would go without houses, and the carpenter would go without work,-to say nothing of the people, who would also go without work, that now make tools for the carpenter.

We build in this country more of brick than of stone, because brick-earth is found almost everywhere, and stone fit for building is found only in particular districts. Bricks used to pay the state a duty of five shillings and tenpence a thousand; and yet at the kilns they were to be bought under forty shillings a thousand which is less than a halfpenny apiece. The government wisely resolved, in 1850,