282

THE MECHANICAL WONDERS OF A FEATHER.

makes a thousand new and admirable combinations. He passes through a thousand imaginary scenes, tries his courage, tasks his ingenuity, and thus becomes gradually prepared to meet almost any of the many-coloured events of human life. If he observes the passengers, he reads their countenances, conjectures their past history, and forms a superficial notion of their wisdom or folly, their virtue or vice, their satisfaction or misery. If he observes the scenes that occur, it is with the eye of an artist. Every object is capable of suggesting to him a volume of reflections.

The time of these two persons in one respect resembles; it has brought them both to Hyde-park Corner. In every other respect how dissimilar!

Probably nothing has contributed so much to generate these opposite habits of mind, as an early taste for reading. Books gratify and excite our curiosity in innumerable ways. They force us to reflect; they present direct ideas of various kinds, and they suggest indirect ones. In a well-written book we are presented with the maturest reflections, or the happiest flights of a mind of uncommon excellence; and it is impossible that we can be much accustomed to such companions, without attaining some resemblance of them.

GODWIN.

LESSON 131.

The Mechanical Wonders of a Feather.

Lamina (plural laminæ,) thin plate, one coat laid over another. EVERY single feather is a mechanical wonder. If we look at the quill, we find properties not easily brought together, strength and lightness. I know few things more remarkable than the strength and lightness of the very pen with which I am now writing. If we cast our eyes towards the upper part of the stem, we see a material made for the purpose, used in no other class of animals, and in no other part of birds; tough, light, pliant, elastic. The pith, also, which feeds the feathers, is neither bone, flesh, membrane, nor tendon. But the most artificial part of a feather is the beard, or as it is sometimes called, the vane; which we usually

THE MECHANICAL WONDERS OF A FEATHER.

283

The

strip off from one side or both when we make a pen. separate pieces of which this is composed are called threads, filaments, or rays. Now, the first thing which an attentive observer will remark is, how much stronger the beard of the feather shows itself to be when pressed in a direction perpendicular to its plane, than when rubbed either up or down in the line of the stem; and he will soon discover, that the thread of which these beards are composed are flat, and placed with their flat sides towards each other; by which means, while they easily bend for the approaching of each other, as any one may perceive by drawing his finger ever so lightly upwards, they are much harder to bend out of their plane, which is the direction in which they have to encounter the impulse and pressure of the air, and in which their strength is wanted. It is also to be observed, that when two threads, separated by accident or force, are brought together again, they immediately reclasp. Draw your finger round the feather which is against the grain, and you break, probably, the junction of some of the contiguous threads; draw your finger up the feather, and you restore all things to their former state. It is no common mechanism by which this contrivance is effected! The threads or laminæ above mentioned are interlaced with one another; and the interlacing is performed by means of a vast number of fibres or teeth which the threads shoot forth on each side, and which hook and grapple together. Fifty of these fibres have been counted in one twentieth of an inch. They are crooked, but curved after a different manner for those which proceed from the thread on the side towards the extremity of the feather are longer, more flexible, and bent downward; whereas those which proceed from the side toward the beginning or quill-end of the feather, are shorter, firmer, and turned upward. When two lamina, therefore, are pressed together, the crooked parts of the long fibres fall into the cavity made by the crooked parts of the others; just as the latch which is fastened to a door, enters into the cavity of the catch fixed to the door-post, and there hooking itself fastens the door! DR. PALEY.

284

ART OF MAKING PINS.

LESSON 132.

Art of Making Pins.

THOUGH pins are apparently simple, their manufacture is, however, not a little curious and complex. When the brass wire, of which the pins are formed, is first received at the manufactory, it is generally too thick for the purpose of being cut into pins. The first operation, therefore, is that of winding it off from one wheel to another with great velocity, and causing it to pass between the two, through a circle in a piece of iron of smaller diameter. The wire being thus reduced to its proper dimensions, is straightened by drawing it between iron pins, fixed in a board in a zigzag manner, but so as to leave a straight line between them; afterwards it is cut in lengths of three or four yards, and then into smaller ones, every length being sufficient to make six pins. Each end of these is ground to a point, which was performed, when I viewed the manufactory, by boys, who sat each withtwo small grinding-stones before him, turned by a wheel. Taking up a handful, he applies the ends to the coarsest of the two stones, being careful at the same time to keep each piece moving round between his fingers so that the points may not become flat: he then gives them a smoother and sharper point by applying them to the other stone, and by that means a lad of twelve or fourteen years of age, is able to point about sixteen thousand pins in an hour. When the wire is thus pointed, a pin is taken off at each end, and this is repeated till it is cut into six pieces. The next operation is that of forming the heads, or, as they term it, headspinning, which is done by means of a spinning-wheel, one piece of wire being thus with astonishing rapidity wound round another, and the interior one being drawn out, leaves a hollow tube between the circumvolutions; it is then cut with shears, every two circumvolutions, or turns of the wire, forming one head; these are softened by throwing them into iron pans, and placing them in a furnace till they are redhot. As soon as they are cold, they are distributed to children, who sit with hammers and anvils before them, which they work with their feet, by means of a lathe, and taking up one of the lengths, they thrust the blunt ends into a

quantity of the heads which lie before them, and catching one at the extremity, they apply them immediately to the anvil and hammer, and by a motion or two of the foot, the top and the head are fixed together in much less time than it can be described, and with a dexterity only to be acquired by practice; the spectator being in continual apprehension for the safety of their fingers' ends. The pin is now finished as to its form, but still it is merely brass; it is therefore thrown into a copper containing a solution of tin and the lees of wine. Here it remains for some time, and when taken out assumes a white, though dull appearance: in order therefore to give it a polish, it is put into a tub containing a quantity of bran, which is set in motion by turning a shaft that runs through its centre, and thus by means of friction it becomes perfectly bright. The pin being complete, nothing remains but to separate it from the bran, which is perfectly similar to the winnowing of corn, the bran flying off, and leaving the pin behind it for immediate sale.

LESSON 133.

Clouds and Rain.

Conge'ries, a mass of small bodies heaped up together. A CLOUD is a collection of vapour, suspended in the atmosphere. In other words, it is a congeries of watery particles raised from the waters, or watery parts of the earth, by the solar or electrical fire. These watery particles, in their first ascent, are too minute. and too much separated by their mutual repulsion, to be perceived; but as they mount higher and higher, meeting with a greater degree of cold, losing their electricity, or by some process employed by Nature for this purpose, they are in a certain degree condensed, and rendered opaque, by the re-union of their parts, so as to reflect and absorb light, and become visible as clouds.

The lowest part of the air being pressed by the weight of the upper against the surface of the water, and continually rubbed upon it by its motion, attracts and dissolves those particles with which it is in contact, and separates them from the rest of the water. And since the cause of solution

is the stronger attraction of the particles of water towards the air than towards each other, those that are already dissolved and taken up will be raised still higher, by the attraction of the dry air, which lies over them, and thus will dif fuse themselves, rising gradually higher and higher, thereby leaving the lower air not so much saturated, but that it will still dissolve and take up fresh particles of water; which process is greatly promoted by the motion of the wind.

When the vapours are thus raised into the higher and colder parts of the atmosphere, some of them will coalesce into small particles, which, slightly attracting each other, and being intermixed with air, will form clouds; and these clouds will float at different heights, according to the quantity of vapour borne up, and to the degree of heat in the upper part of the atmosphere. The clouds, therefore, are generally higher in summer than in winter; in the former season they are from one mile to three miles high, and in the latter from a quarter of a mile to a mile.

When the clouds are much increased by a continual addition of vapours, and their particles are driven close together by the force of the winds, they will run into drops heavy enough to fall down in rain. If the clouds are frozen before their particles are gathered into drops, small pieces of them being condensed, and made heavier by the cold, they fall down in flakes of snow. If the particles are formed into drops before they are frozen, they become hailstones. When the air is replete with vapours, and a cold breeze springs up which checks the solution of them in the air, clouds are formed in the lower parts of the atmosphere, and these compose a mist or fog: this usually happens in a cold morning; but the mist is dispersed when the sun has warmed the air, and made it capable of dissolving the watery particles of which the mist is composed.

Southerly winds generally bring rain, because, being commonly warm, and replete with aqueous vapours, they are cooled by passing into a colder climate; and therefore part with some of them, and suffer them to precipitate in rain: northerly winds, on the contrary, being cold, and acquiring heat by coming into a warm climate, take up or dissolve more vapour than they before contained; and therefore are dry and parching, and usually attended with fair weather.

GREGORY.