Chapter XX (4)

The foot has five toes, at the end of each of which, except that of the thumb, is a very sharp and much curved claw; on the under surface of each toe are sixteen transverse slits, leading to so many cavities or pockets, the depth of which is nearly equal to the length of the slit that forms the orifice; they all open forward, and the external edge of each opening is serrated, like the teeth of a small-toothed comb. The cavities, or pockets, are lined with a cuticle, and the serrated edges are also covered with it. The structure just described is supplied with various muscles, whose action is to draw down the claw, open the orifices of the pockets, and turn down the serrated edges upon the surface on which the animal stands. Upon examining attentively the under surface of the toes, when the pockets are closed, Sir Everard Home was struck with their resemblance to the surfaces of that portion of the _Echineis remora_, or sucking fish, by which it attaches itself to the shark, or to the bottom of ships; and it consequently suggested the probability of obtaining, from an examination of this latter apparatus, much useful information which might be applicable to the subject of the lizard, more especially as the parts of which it is composed are so much larger, and therefore more within the reach of anatomical examination.

The surface on the top of the head of this fish, fitted for adhesion, is of an oval form, and bears a considerable proportion to the size of the whole animal; it is surrounded by a broad, loose, movable edge, capable of applying itself closely to the surface on which it is placed; and it is evident that when the external edge is so applied, and the cartilaginous plates are raised up, the interstices must become so many vacua, and the serrated edge of each plate will keep a sufficient hold of the substance on which it rests to retain it in that position, assisted by the pressure of the surrounding water, without a continuance of muscular exertion. It thus appears that the adhesion of the _sucking fish_ is produced by so many vacua being formed through an apparatus worked by the voluntary muscles of the animal, and the pressure of the surrounding water.

From the similarity of the mechanism of the under surface of the toes of the _lacerta gecko_, there can be no doubt that the purpose to which it is applied is the same: but as in the one case the adhesion is to take place under water, and is to continue for longer periods, the means are more simple; in the other, where the mechanism is to be employed in air, under greater disadvantages with respect to gravity, and is to last for very short periods, and then immediately afterwards to be renewed, a more delicate structure of parts, a greater proportional depth of cavities, and more complex muscular structure, become necessary.

Having ascertained the principle on which an animal of so large a size as the _lacerta gecko_ is enabled to support itself in its progressive motion against gravity, Sir E. Home felt himself more competent to inquire into the mechanism by which the common fly is enabled, with so much facility, to support itself in still more disadvantageous situations. In the natural size the feet of the fly are so small, that nothing can be determined respecting them; Keller was the first person who made a drawing of the fly’s foot in a highly magnified state, in which the concave surfaces are visible, and which, no doubt, like those of the lizard above described, are employed to form vacua, which enable the fly to move under such disadvantageous circumstances. Mr. Bauer, who has so greatly distinguished himself in microscopic researches, was judiciously enlisted into the service of Sir E. Home upon this occasion; and he has shown that this principle, on which progressive motion against gravity depends, is very extensively employed by nature in the structure of the feet of insects; and Sir Everard observes, that, now this structure is known, it can be readily demonstrated by looking at the movement of the feet of any insect upon the inside of a glass tumbler, through a common magnifying glass; the different suckers are readily seen separately to be pulled off from the surface of the glass, and reapplied to another part.

In consequence of the expedition to the polar regions, Sir E. Home was enabled to obtain and examine the foot of the walrus, in which he detected a resemblance in structure to that of the fly; and it is not a little curious that two animals so different in size should have feet so similar in their use. In the fly the parts require to be magnified one hundred times to render the structure distinctly visible; and in the walrus the parts are so large, as to require being reduced four diameters, to bring them within the size of a quarto page.

Nor is progressive motion, the only function in which Nature avails herself of the pressure of the atmosphere for the accomplishment of her purposes. The act of feeding is continually effected in this manner. The operation of sucking is too familiar to require comment. It may not, perhaps, be so generally known, that it is by the very same process that bees reach the fine dust and juices of hollow flowers, like the honeysuckle, and some species of foxglove, which are too narrow to admit them. They fill up the mouth of the flower with their bodies, and suck out the air, or at least a large portion of it, by which the soft sides of the flower are made to collapse, and the juice and dust are squeezed towards the insect, as completely as if the hand had pressed it externally. It is by a similar process that the oyster is enabled to close its shell so firmly; for, if a hole be bored in it, it may be opened without the least difficulty.

Note 29, p. 191.--ACCIDENTAL DISCOVERIES.

Those who are not acquainted with the operations by which the mind is enabled to arrive at truth, are too apt to attribute to accident that which is the result of great intellectual labour and acuteness. Observation, analogy, and experiment are the three great stepping-stones by which the philosopher is enabled to ascend from darkness to light: it is true that his foot may accidentally be placed upon the first, but his own efforts are required to complete the ascent. To the mass of mankind the preliminary step is obvious, and they at once conclude that the succeeding ones are equally easy and simple. In this view of the subject, it was by accident that Sir Isaac Newton discovered the laws of gravitation, for his mind was directed to the investigation by the accidental fall of an apple from its tree; it was by accident that Galileo discovered the isochronous movement of the pendulum, for it was suggested by the vibration of a chandelier: but how many persons might have witnessed the fall of an apple, or the vibration of a chandelier, without arriving at similar truths? It has been said that we are indebted for the important invention in the steam-engine, termed _hand gear_, by which its valves or cocks are worked by the machine itself, to an idle boy of the name of Humphrey Potter, who, being employed to stop and open a valve, saw that he could save himself the trouble of attending and watching it, by fixing a plug upon a part of the machine which came to the place at the proper times, in consequence of the general movement. If this anecdote be true, what does it prove? That Humphrey Potter might be very idle, but that he was, at the same time, very ingenious. It was a contrivance, not the result of accident, but of acute observation and successful experiment. Glass is said to have been discovered by persons having accidentally kindled a fire on the sandy shore with sea-weed, when the alkali from the ashes united with the silex of the sand; and Pliny tells us that _minium_, or red lead, was first recognised, in consequence of a fire that took place at the Piræus at Athens, where some _ceruse_, which had been exposed to the fire, had been found converted into a red substance. A thousand such accidents might be related, were we not affording a sample rather than a catalogue. We are endeavouring to combat a popular but mischievous error; and we are happy at finding the same feeling expressed in a work which, from its extensive circulation, must prove highly useful in correcting it. “Very few discoveries,” says the author, “have been made by chance and by ignorant persons; much fewer than is generally supposed. They are generally made by persons of competent knowledge, and who are in search of them. The improvement of the steam-engine by Watt resulted from the most learned investigation of mathematical, mechanical, and chemical truths. Arkwright devoted many years, five at least, to his invention of spinning-jennies. The new process of refining sugar, by which more money has been made in a shorter time, and with less risk and trouble, than was perhaps ever gained by an invention, was discovered by Mr. Howard, a most accomplished chemist, and it was the fruit of a long course of experiments, in the progress of which, known philosophical principles were constantly applied, and one or two new principles ascertained.”--_Library of Useful Knowledge._

Note 30, p. 193.--WEIGHT OF THE SUPERINCUMBENT OCEAN.

If we include the pressure of the atmosphere, a body at the depth of 100 feet would sustain that of 60 pounds on the square inch; while one at 4,000 feet, a depth by no means considerable, it would be exposed to a pressure of about 1,830 pounds. We need not, therefore, feel surprised, that on the foundering of a ship at sea, though its timbers part, not a spar floats to the surface; for if the hull has sunk to a great depth, all that is porous is penetrated with water or greatly compressed. Captain Scoresby states that when, by the entangling of the line of the harpoon, a boat was carried down with the whale, it required after it was recovered two boats to keep it at the surface. Sir J. Herschel has recorded a melancholy anecdote, which may well be adduced in farther illustration of our subject:--“After the invention of the diving-bell, and its success in sub-aqueous processes, it was considered highly desirable to devise some means of remaining for any length of time under water, and rising at pleasure without any assistance. Some years ago an ingenious individual proposed a project by which this end was to be accomplished. It consisted in sinking the hull of a ship made quite water-tight, with the decks and sides strongly supported by shores, and the only entry secured by a stout trap-door, in such a manner, that by disengaging from within the weights employed to sink it, it might rise of itself to the surface. To render the trial more satisfactory, the projector himself made the first essay. It was agreed that he should sink in twenty fathoms water, and rise again without assistance at the expiration of twenty-four hours. Accordingly, making all secure, and provided with the means of making signals to indicate his situation, this unhappy victim of his own ingenuity entered and was sunk. No signal was made, and the time appointed elapsed. The pressure of the water at so great a depth had, no doubt, been completely under-estimated, and the sides of the vessel being at once crushed in, the unfortunate projector perished, before he could even make the signal concerted to indicate his distress.”

Note 31, p. 199.

Hence _pecunia_ from pecus. _Opes_ quasi Oves. See Note 6.

Note 32, p. 207.--THE CAUSE OF IRIDESCENCE.

If a soap-bubble be blown up, and set under a glass, so that the motion of the air may not affect it, as the water glides down the sides and the top grows thinner, several colours will successively appear at the top, and spread themselves from thence in rings down the sides of the bubble, till they vanish in the same order in which they appeared; at last a black spot appears at the top, and spreads till the bubble bursts. Hence it follows that the colours of a body depend in some degree upon the thickness and density of the particles that compose it; and that, if the density be changed, the colour will likewise be changed. That the production of colours depends upon the nature of the surfaces upon which light falls, is beautifully exemplified by the iridescence of mother of pearl; and which has been satisfactorily shown to depend upon a singular peculiarity in the structure of that substance. On its surface, which to the unassisted eye, and even to the touch, appears to be finely polished, there are innumerable little lines, or _grooves_, in some places as many as two or three thousand in the space of an inch, which, lying parallel, regularly follow each other in all their windings; by the edges of which the rays of light are reflected, and the continual change of colour arises from their continual bendings. Whatever doubts might have existed upon the subject, some late experiments of Dr. Brewster have dissipated them, by showing that the colours which play so beautifully on the surface of mother of pearl, may be communicated by pressure to sealing-wax and several other substances. The discovery of this fact was in some measure accidental; he had stuck a piece of mother of pearl on a cement made of rosin and bees-wax, and on separating this cement he found that it had acquired the property of exhibiting colours. Several persons who witnessed the effect, concluded that it arose from the presence of a thin film of the mother of pearl, which might have scaled off and adhered to the wax: but such an explanation was at once refuted, by plunging the wax in acid, which must have dissolved the mother of pearl, had any been present; but the acid had no effect, and the colours of the impression remained unimpaired. It is clear, then, that it is the grooves, as Dr. Brewster conjectured, which occasion the iridescence in the mother of pearl, as well as in the waxen impression. In consequence of this curious discovery, Mr. Barton succeeded in producing the same appearance on glass, and on different metals, by simply cutting grooved lines on their surface. These lines are so fine that, without a microscope, they are scarcely visible, and the glass and the metal appear to retain their polish: yet they and the colours also may be communicated by an impression, like those from the mother of pearl, to the wax. In like manner the varying and delicate hues exhibited by the wings of certain butterflies, arise from the action of light upon the parallel and equidistant striæ upon their surfaces.

Note 33, p. 224.--VEGETABLE BAROMETERS.

The following are a few of those plants which indicate changes in the weather:--

_Chickweed_ is an excellent barometer. When the flower expands fully, we are not to expect rain for several hours; should it continue in that state, no rain will disturb the summer’s day. When it half conceals its miniature flower, the day is generally showery; but, if it entirely shuts up, or veils the white flower with its green mantle, let the traveller take the hint and put on his great-coat. The different species of _trefoil_ always contract their leaves at the approach of a storm; so certainly does this take place, that these plants have acquired the name of the _husbandman’s barometer_.

The tulip and several of the compound yellow flowers also close before rain. There is, besides, a species of wood-sorrel, which doubles its leaves before storms and tempests. The _bauhinia_, or mountain ebony, _cassia_, and sensitive plants, observe the same habit.

Note 34, p. 225.--SAINT SWITHIN.

The popular adage of _Forty days’ rain after St. Swithin_, is a tradition which seems to have derived its origin from the following circumstance. Swithin, or _Swithum_, bishop of Winchester, who died in 868, desired that he might be buried in the open church-yard, and not in the chancel of the minster, as was usual with other bishops; and his request was complied with; but the monks, on his being canonized, considering it disgraceful for the saint to lie in a public cemetery, resolved to remove the body into the choir, which was to have been done with solemn procession on the 15th of July. It rained, however, so violently for forty days together at this season, that the design was abandoned. “Now, without entering into the case of the bishop,” says Mr. Howard, in his work on the Climate of London, “who was probably a man of sense, and wished to set the example of a more wholesome, as well as a more humble, mode of resigning the perishable clay to the destructive elements, I may observe, that the fact of the hindrance of the ceremony by the cause related is sufficiently authenticated by tradition; and the tradition is so far valuable, as it proves that the summers in this southern part of our island, were subject, a thousand years ago, to occasional heavy rains, in the same way as at present.” Mr. Howard has shown, by a table, that the notion commonly entertained on this subject, if put strictly to the test of experience, at any one station, in this part of the island, will be found fallacious; he, however, very justly observes, that “the opinion of the people on subjects connected with Natural History is commonly founded, in some degree, on fact or experience;” and to do justice to the popular observation in question, he states that, “in a majority of our summers, a showery period, which, with some latitude as to time and local circumstances, may be admitted to constitute daily rain for forty days, does come on about the time indicated by this tradition; not that any long space before is often so dry as to mark distinctly its commencement.”

Note 35, p. 230.--THE WHALE.

Did the whale know his own power, he would easily destroy all the machinery which the art of man could devise for catching him; it would be only necessary for him to swim on the surface in a straight line in order to break the thickest rope; but the fish, on being struck by the harpoon, obeys a natural instinct, which, in this instance, betrays him to his death. Sir H. Davy, in his Salmonia, observes, that the whale, not having an air-bladder, can sink to the lowest depths of the ocean, and mistaking the harpoon for the teeth of a sword-fish, or a shark, he instantly descends, this being his manner of freeing himself from these enemies, who cannot bear the pressure of a deep ocean; and from ascending and descending in small space, he thus puts himself in the power of the whaler.--_See Note 30._

Note 36, p. 235.--PROGRESSIVE MOTION IN FISHES:
BOATS IMPELLED BY PADDLING, ROWING, &C.

To render the subject to which this note refers farther intelligible, we may show the means by which a fish moves forward in the water. The accompanying diagram and demonstration are from Dr. Roget’s Bridgewater Treatise.

The tail is the principal instrument by which the progressive motion is effected. Thus--suppose that the tail is inclined to the right; if, in this situation, the muscles of the left side, tending to bring the tail in a right line with the body, are suddenly thrown into action, the resistance of the water, by reacting against the broad surface of the tail in the direction P R, perpendicularly to that surface, will cause the muscular action to give the whole body an impulse in that direction; and the centre of gravity, C, will move onwards in the direction C B, parallel to P R. This impulse is not destroyed by the farther flexion of the tail towards the left side, because the principal force exerted by the muscles has already been expended in the motion from R to M, in bringing it to a straight line with the body; and the force which carries it on to L is much weaker, and therefore occasions a more feeble reaction. When the tail has arrived at the position L, indicated by the dotted outline, a similar action of the muscles on the right side will create a resistance and an impulse in the direction of K L, and a motion of the whole body in the same direction, C A. These impulses being repeated in quick succession, the fish moves forward in the diagonal C D, intermediate between the direction of the two forces.

Upon the same principle a boat is impelled by paddling; and the action of the rudder of a ship in turning the vessel will be readily understood. In this latter case, however, there is an additional mechanical advantage; since the point round which the vessel turns, is beyond the middle and towards the prow, and hence the force applied at the extremity of the keel acts as by an arm of a lever.

Note 37, p. 236.--FLIGHT OF BIRDS.

In appreciating the mechanical means by which a bird is enabled to direct its course, we must not omit to take into account the power it possesses of changing the position of the centre of gravity of its body, so that the reaction of the air may be modified with regard to each wing.

Note 38, p. 236.--FLIGHT OF INSECTS.

The command possessed by insects in directing and changing their course, seems more perfect even than that of birds. Many of them travel on their wings to immense distances, and, considering their comparative size, they generally move through the air with greater velocity than that of birds. Bees have been known to fly great distances from their hive, in search of food; and the silk-worm moth has travelled more than a hundred miles in a very short space of time. Many of our readers have, no doubt, noticed with surprise the apparent facility with which gnats have accompanied them, although they may have been advancing on horseback at a full gallop; and the author during the last summer has been forcibly struck with the manner in which flies and other insects have kept up with a railway carriage, alternately flying in and out of the vehicles, as though they had been at perfect rest. Some species possess a remarkable power of poising themselves in the air, and hovering for a length of time over the same spot, without falling or rising, advancing or retreating; the _Dragon-fly_ affords a striking example of this fact.

Note 39, p. 237.--OBLIQUITY OF THE WINGS OF BIRDS.

In consequence of the manner in which the wings are affixed to the scapula, they give a stroke to the air in a direction both downwards and backwards; so that while the former supports the bird, the latter impels it forward. It is curious to notice that the degree of this obliquity varies in different birds, and is evidently adapted to their habits: thus, for instance, birds of prey have a great obliquity of wing, which better enables them to pursue their victims in a horizontal course; while those birds which soar to a considerable elevation, in a nearly vertical direction, as the _Lark_, have scarcely any obliquity of wing, but strike directly downwards.

Note 40, p. 238.--A MECHANICAL PROPOSITION.

This fact may be demonstrated by converting the triangle into a parallelogram, of which one of the sides of the triangle will become its diagonal: the other two sides will, of course, represent two forces equivalent to such diagonal, which, acting in opposition to it, must produce a balance.

Note 41, p. 241.--KITE MESSENGERS.

The curious experiments of Mr. Faraday upon the optical effects produced by the revolutions of different wheels, might be exhibited by arrangements adjusted as messengers.

Note 42, p. 246.--WINDS AND STORMS.

The sea and land breezes which occur in the islands of the torrid zone, very strikingly illustrate the position laid down in the text, and afford a good explanation of the manner in which winds may be occasioned by a change of temperature in the air. In these, during the hottest part of the day, the wind sets in from all quarters, and appears to be blowing towards the centre of the island, while in the night it changes its direction, and blows from the centre of the land towards the sea; for since the sun’s rays produce much more heat by their reflection from land than they do from water, that portion of air which is over the land will soon become heated, and will ascend; a rarefaction and diminution of the quantity of air over the central part of the land will be thus occasioned, which must be supplied from the sides; but, as the land cools again during the night, that portion of air which had been previously heaped up will begin to descend, and by spreading and equalizing itself will produce a breeze blowing from the centre.

The _trade-winds_, so called from the advantage which their certainty affords to trading vessels, are another example of the same kind; they are generally stated to blow from east to west over the equator, and are occasioned by the rarefaction of the air by the sun’s heat, and the motion of the earth from west to east. While writing the present note, we have seen an essay upon the subject by Captain Basil Hall, published in an appendix to Mr. Daniel’s admirable work on Meteorology: the perusal of this paper has induced us to cancel what we had written, and to refer the reader to the essay itself; for it is quite impossible to do justice to the views it entertains, in the limited space necessarily prescribed to us in this note.

On the coast of Guinea, the wind always sets in upon the land, blowing westerly instead of easterly; this exception arises from the deserts of Africa, which lie near the equator, and being a very sandy soil, reflect a great degree of heat into the air above them, which being thus rendered lighter than that which is over the sea, the wind continually rushes in upon the land to restore the equilibrium.

Among the irregular winds, or those which are not constant, but accidental, may be noticed the _whirlwind_, the _harmattan_, and the _sirocco_. The first of these is occasioned by the meeting of two or more currents of wind from opposite directions, and which can only be occasioned by some temporary but violent disturbance of equilibrium. The _harmattan_ is met with on the western coast of Africa, and is generally attended by great heat and fog; it appears to be occasioned by a conflict between the heated sands of Africa, and the regular direction of the trade-winds over that continent, and, by disturbing their progress, it is frequently the forerunner of a hurricane in the West Indies. The _sirocco_ occurs in Egypt, the Mediterranean, and in Greece, and is chiefly characterised by its unhealthy qualities. The air, by passing over the heated sands of Egypt, becomes so dried and rarefied as to be scarcely fit for respiration, and, being thus prepared, it absorbs so much humidity on passing the Mediterranean as to form a suffocating and oppressive kind of fog.

Mr. Daniel observes, that the currents of a heated room, in some measure, exemplify the great currents of the atmosphere. If the door be opened, the flame of a candle held to the upper part will show, by its inclination, a current flowing outwards; but, if held near the floor, it will be directed inwards. If the door be closed suddenly from without, it moves with the in-coming current, and against the out-going, and a condensation of air takes place in the room; which is proved by the rattling of the windows, and the bursting open of any door in the room, if slightly closed. If the door close from within, it moves against the in-coming current, and with the out-going, and a rarefaction of the air in the room takes place; which is evidenced by the rattling of the windows, and the bursting open of another door in the contrary direction.

Meteorology has been long considered the least perfect branch of natural knowledge; so apparently capricious and irregular are its phenomena, that philosophers had almost abandoned the idea of bringing them under the operation of any general laws. Brighter lights are, however, now dawning upon us. Mr. Whewell, in his Bridgewater Treatise, has explained the manner in which the various currents of the atmosphere maintain a necessary balance in the distribution of heat and moisture around the globe, and has thus reduced to order and design phenomena which have hitherto been regarded as unconnected and fortuitous. Lieut.-Col. Reid, by his late happy investigation of the law of storms, will, no doubt, lead us into a novel path of the most important discoveries. He has satisfactorily proved, by a mass of evidence derived from numerous logbooks, that storms obey fixed laws. His attention was ardently directed to the subject by having been at Barbadoes immediately after the great hurricane of 1831, which in the short space of seven hours killed upwards of 1400 persons on that island alone. The discoveries of Col. Reid may be thus briefly stated.--That hurricanes are whirlwinds of great diameter, always revolving according to an invariable law, viz. from right to left (supposing yourself standing in the centre), or in the opposite way to the hands of a watch, in the northern hemisphere, and in a contrary direction in southern latitudes; at the same time they have a progressive motion in a curved line, and as they advance their diameters appear to enlarge and their violence to diminish; it has been also found that in the centre of the vortex there is a lull, or calm. Col. Reid observes that the simplest mode of illustrating the subject is to cut out concentric circles, so as to represent progressive whirlwinds, by moving which over any tract, the veering of the wind will be easily understood. The reader may form a more familiar idea by causing the water to circulate in a basin, which will represent the violent circular motion of the storm-wind, with a calm in the centre of the vortex. Suppose this to be also moving onward at a rate of about seven miles an hour, and he will have a correct notion of the subject. Since the storms expand in size and diminish in force as they proceed towards the poles, and the meridians at the same time approach each other, gales become huddled together; and hence, apparently, the true cause of the very complicated nature of the winds in our latitude. Observations would also appear to render it probable that there exists an accordance of the force of storms with the law of magnetic intensity; for example, it is at its minimum at St. Helena, where storms never occur; on the contrary, the lines of greatest intensity seem to correspond with the latitudes of typhoons and hurricanes. To what important discoveries may not the pursuit of this enquiry lead us?

The practical importance of the foregoing facts must be obvious: to use the expression of Sir John Herschel, “they will teach seamen how to steer their ships, and save thousands of lives.” They will thus learn on which side to lay-to a ship in a storm, for, by watching the veering of the wind, they will ascertain the direction in which it is falling; if violent, and the changes sudden, the ship will probably be near the centre of the vortex; whereas, if the wind blows a great length of time from the same point, and the changes are gradual, it may reasonably be supposed the ship is near the extremity of it. The barometer also becomes a very important instrument upon these occasions; the rapid rotatory motion of a column of the atmosphere necessarily occasions its fall, and this fall is always greatest at the centre of the storm. When it begins to rise, the centre has passed, and when the wind has sufficiently abated to enable a ship to make sail, she may then bear away with safety; but near the middle of the hurricane, before the barometer begins to rise, all square-sails must be dangerous.

Note 43, p. 250.--ANCIENT ARCHERY.

We are reminded, upon this occasion, of part of a stanza in the well-known ballad of Chevy Chace, where an English archer aimed his arrow at Sir Hugh Montgomery:--

“The _grey goose wing_ that was thereon,
In his hearte’s blood was wett.”

The more ancient ballad, however, reads _swane-feathers_. In the “Geste of Robyn Hode,” among Mr. Garrick’s old plays, in the Museum, the arrows of the outlaw and his companions are particularly described:--

“With them they had an hundred bowes,
The strings were well ydight;
An hundred shefe of arrows good,
With hedes burnish’d full bryght;
And every arrowe an ell longe,
With _peacocke_ well ydight,
And rocked they were with white silk,
It was a semely sight.”

And Chaucer, in the description of the squyer’s yeoman, says:--

“And he was clad in cote and hode of greene;
A sheafe of _peacocke_ arrows bryght and shene,
Under his belt he bare full thriftely,
Well coude he dresse his tackle yemanly:
His arrowes drouped not with fethers lowe,
And in his hand he bare a mighty bowe.”
_Prol. to Cant. Tales._

In order to show the dandyism displayed by the archers of former times, it may be stated, that, in the wardrobe accounts of the 28 Edw. I. p. 359, is a charge for verdigrise to stain the feathers of the arrows green. A wardrobe account of the 4 Edw. II. furnishes an entry for peacock arrows, “Pro duodecim flecchiis cum pennis de _pavone_, emptis pro rege de 12 den.”

As this note has some connexion with the shuttlecock,[84] as well as the arrow, we may take this opportunity of introducing a passage, which was accidentally omitted in the text; it refers to the method of playing this game at Turon, in Cochin China; and which is described by a traveller as follows:--“Instead of using a battledoor,[85] as is the custom in England, the players stood seven or eight in a circle; and after running a short race, and springing from the floor, they met the descending shuttlecock with the sole of the foot, and drove it up again with force high in the air. The game was kept up with much animation, and seldom did the players miss their stroke, or give it a wrong direction. The shuttlecock was made of a piece of dried skin rolled round, and bound with strings. Into this skin were inserted three feathers, spreading out at top, but so near to each other, where they were stuck into the skin, as to pass through the holes, little more than a quarter of an inch square, which were always made in the centre of Cochin copper coins. We made one or two awkward attempts at the game, not only to our own confusion, but much to the amusement of the natives. It must, however, be remembered, that, amongst these ingenious people, the feet assist, as auxiliaries to the hands, in the exercise of many trades, particularly that of boat-building.”

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Footnote 84:

Shuttlecock, more correctly, perhaps, shuttle-_cork_, although
Skinner thinks it is called a _cock_ from its feathers.

Footnote 85:

So called from door, taken for a flat board; and battle, for
striking, _i. e._ a striking-board.

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Note 44, p. 270.--SOUND CONVEYED BY SOLID BODIES.

A beautiful experiment was lately instituted at Paris, to illustrate this fact, by Biot. At the extremity of a cylindrical tube, upwards of 3000 feet in length, a ring of metal was placed, of the same diameter as the aperture of the tube; and in the centre of this ring, in the mouth of the tube, was suspended a clock-bell and hammer. The hammer was made to strike the ring and the bell at the same instant, so that the sound of the ring would be transmitted to the remote end of the tube through the conducting power of the matter of the tube itself; while the sound of the bell would be transmitted through the medium of the air included within the tube. The ear being then placed at the remote end of the tube, the sound of the ring, transmitted by the metal of the tube, was first distinctly heard; and, after a short interval had elapsed, the sound of the bell, transmitted by the air in the tube, was heard. The result of several experiments was, that the metal of the tube conducted the sound with about ten and a half times the velocity with which it was conducted by the air; that is, at the rate of about 11,865 feet per second.

Note 45, p. 288.--EXPRESSIVE MUSIC.

The biographer of Josquin des Prez, the celebrated musician, and _maestro di capella_ to Louis XII. King of France, relates an anecdote which may be here told in connexion with the present subject. When Josquin was first admitted into the service of the French monarch, he had been promised a benefice by his Majesty; but this Prince, contrary to his usual habits, for he was in general both just and liberal, forgot the promise he had made; when Josquin, after suffering great inconvenience from the shortness of his Majesty’s memory, ventured by the following expedient to remind him publicly of his promise without giving offence. He had been commanded to compose a motet for the Chapel Royal, on which occasion he selected part of the 119th Psalm, “_Memor esto verbi tui servo tuo_”--“_Oh think of thy servant, as concerning thy word_,” which he set in so supplicating and exquisite a manner, that it was universally admired, particularly by the King, who was not only touched by the music, but felt the words so effectually, that he soon afterwards granted his petition, by conferring on him the promised preferment. For which act of justice and munificence, Josquin, with equal felicity, composed as a hymn of gratitude another part of the same Psalm,--“_Bonitatem fecisti cum servo tuo, Domine_”--“_Oh Lord, thou has dealt graciously with thy servant._”

Josquin, among musicians, was the giant of his time, and seems to have arrived at universal monarchy and dominion over the affections and passions of the musical part of mankind; indeed, his compositions were as well known and as much practised throughout Europe at the beginning of the sixteenth century, as those of Handel were in Europe sixty years ago.

Note 46, p. 294.--IMAGINARY FORMS.

The following case, quoted by Sir David Brewster, in his work on “Natural Magic,” from the life of Peter Heaman, a Swede, who was executed for piracy and murder at Leith in 1822, will afford a very curious example of the influence of the imagination in creating distinct forms out of an irregularly shaded surface. “One remarkable thing was, one day as we mended a sail, it being a very thin one, after laying it upon deck in folds, I took the tar-brush and tarred it over in the places which I thought needed to be strengthened. But when we hoisted it up, I was astonished to see that the tar I had put upon it represented a gallows and a man under it without a head. The head was lying beside him. He was complete, body, thighs, legs, arms, and in every shape like a man. Now, I oftentimes made remarks upon it, and repeated them to the others. I always said to them all, ‘You may depend upon it that something will happen.’ I afterwards took down the sail on a calm day, and sewed a piece of canvass over the figure to cover it, for I could not bear to have it always before my eyes.”

The curious effect of chance resemblance was particularly remarked by Leonardo da Vinci in the moss and stains on old stones. And, in our own times, this faculty of the imagination has not unfrequently been enlisted into the service of the fortune-teller for purposes of fraud and imposition. The following story is related on credible testimony. “A British officer, in expectation of promotion, and of being united to a lady in marriage, sought a gipsy fortune-teller. The sorceress, no doubt, had made herself well acquainted with these circumstances. On entering the room, she ordered a large glass of spring-water, into which she poured the white of a newly-laid egg. After shaking the mixture for some time, she so far succeeded as to induce the credulous observer to declare that he saw most distinctly the image of the ship in which he was to hoist his flag, the church in which he was to be married, and his bride going with him into the church.”--_The Gipsies’ Advocate_, by J. Crabb.

Note 47, p. 295.--FAIRY RINGS.

Dr. Wollaston, in a paper published in the Philosophical Transactions, (1807, p. 133,) relates some interesting observations he made on the progressive changes of these rings, and which satisfactorily explain their origin. He observed, that some species of fungi were always to be found at the exterior margin of the dark ring of grass if examined at the proper season. The position of the fungi led him to believe, that progressive increase from a central point was the probable mode of formation of the ring; and he thought it likely that the soil which had once contributed to the support of fungi, might be so exhausted as to be rendered incapable of producing a second crop. The defect of nutriment on one side would occasion the new roots to extend themselves solely in the opposite direction, and would cause the circle of fungi continually to proceed, by annual enlargement, from the centre outwards. The luxuriance of the grass follows as a natural consequence, as the soil of an interior circle is enriched by the decayed roots of fungi of the succeeding year’s growth. During the growth of fungi, they so entirely absorb all nutriment from the soil beneath, that the herbage is often for a while destroyed, and a ring appears bare of grass, surrounding the dark ring; but, after the fungi have ceased to appear, the soil where they had grown becomes darker, and the grass soon vegetates again with peculiar vigour. Dr. Wollaston had many opportunities of remarking, that, when two circles interfere with each other’s progress, they do not cross each other, but are invariably obliterated between the points of contact. The exhaustion occasioned by each obstructs the progress of the other, and both are _starved_; a circumstance which affords a strong confirmation of the above theory.

Note 48, p. 300.--RESONANCE.

In order to comprehend the nature of _reciprocated vibration_, or _resonance_, let the reader keep in his remembrance the analogy between musical vibration, and the oscillation of the pendulum, as explained at page 275. If he well understands the phenomena of the latter, he will readily comprehend those of the former. Galileo observed that a heavy pendulum might be put in motion by the least breath of the mouth, _provided the blasts were often repeated, and made to keep time exactly with the vibrations of the pendulum_: from the same sympathetic communication of vibrations will two pendulum clocks fixed to the same wall, or two watches lying upon the same table, take the same rate of going, though they would not agree with one another if placed in separate apartments. Mr. Ellicot indeed observed that the pendulum of one clock was even able to stop that of the other; and that the stopped pendulum, after a certain time, would resume its vibrations, and in its turn stop the vibrations of the other. We have here a correct explanation of the phenomena of _Resonance_; for the undulations excited by a vibratory body are themselves capable of putting in motion all bodies whose pulses are coincident with their own, and consequently with those of the primitive sounding body; hence the vibrations of a string, when another, tuned in unison with it, is made to vibrate.

Upon the same principle does the resonance, or reciprocated vibrations of columns of air, depend. We are much indebted to Mr. Wheatstone for our knowledge of this branch of acoustics; he has shown that, if a tuning-fork or a bell be sounded before a tube inclosing a column of air of the necessary length, the original sound will be augmented by the rich resonance of that air; and that the sounds of tuning-forks, if held before the cavity of the mouth, may be reciprocated most intensely by adjusting the alterable volume of air contained within it to the pitch of the instrument; by placing, for instance, the tongue, &c. in the position for the nasal continuous sound of _ng_ (in song), and then altering the aperture of the lips, until the loudest sound was obtained, he readily accomplished his object.

If two vibrating tuning-forks, differing in pitch, be held over a closed tube, furnished with a moveable piston, either sound may be made to predominate, by so altering the piston as to obtain the exact column of air which will reciprocate the required sound. The same result may be obtained by selecting two bottles (which may be tuned with water) each corresponding to the sound of a different tuning fork; on bringing both tuning-forks to the mouth of each bottle alternately, that sound only will be heard, in each case, which is reciprocated by the unisonant bottle; or, in other words, by that bottle which contains a column of air susceptible of vibrating in unison with the fork.

Among the Javanese instruments brought to England by the late Sir Stamford Raffles, there is one called the _gender_, in which the resonances of columns of air are employed to augment, we might almost say to render audible, the sounds of vibrating metallic plates. Under each of these plates is placed an upright bamboo, containing a column of air of the proper length to reciprocate the lowest sound of such plate. If the aperture of the bamboo be covered with pasteboard, and its corresponding plate be struck, a number of acute sounds only (depending on the more numerous subdivisions of the plate) will be heard; but, on removing the pasteboard, an additional deep rich tone is produced by the resonance of the column of air within the tube.

It is only by a knowledge of this principle that the theory of the Guimbarde, or Jew’s harp, can be well understood.

Note 49, p. 300.--THE JEW’S HARP.

The Memoires of Madame de Genlis first made known the astonishing powers of a poor German soldier on the Jew’s harp. This musician was in the service of Frederick the Great, and finding himself one night on duty under the windows of the king, played the Jew’s harp with so much skill, that Frederick, who was a great amateur of music, thought he heard a distinct orchestra. Surprised on learning that such an effect could be produced by a single man with two Jew’s harps, he ordered him into his presence; the soldier refused, alleging that he could only be relieved by his colonel; and that, if he obeyed, the king would punish him the next day for having failed to do his duty. Being presented the following morning to Frederick, he was heard with admiration, and received his discharge and fifty dollars. This artist, whose name Madame de Genlis does not mention, is called Koch; he has not any knowledge of music, but owes his success entirely to a natural taste. He has made his fortune by travelling about, and performing in public and private; and is now living retired at Vienna, at the advanced age of more than eighty years. He used two Jew’s harps at once, in the same manner as the peasants of the Tyrol; and produced, without doubt, the harmony of two notes struck at the same moment, which was considered by the musically-curious as somewhat extraordinary, when the limited powers of the instrument were remembered. It was Koch’s custom to require that all the lights should be extinguished, in order that the illusion produced by his playing might be increased.

It was reserved, however, for Mr. Eulenstein to acquire a musical reputation from the Jew’s harp. After ten years of close application and study, this young artist has attained a perfect mastery over this untractable instrument. In giving some account of the Jew’s harp, considered as a medium for musical sounds, we shall only present the result of his discoveries. This little instrument, taken singly, gives whatever grave sound you may wish to produce, as a _third_, a _fifth_, or an _octave_. If the grave tonic is not heard in the bass Jew’s harp, it must be attributed not to the defectiveness of the instrument, but to the player. In examining this result, you cannot help remarking the order and unity established by nature in harmonical bodies, which places music in the rank of exact sciences. The Jew’s harp has three different tones; the bass tones of the first octave bear some resemblance to those of the flute and clarionet; those of the middle and high to the _vox humana_ of some organs; lastly, the harmonical sounds are exactly like those of the _harmonica_. It is conceived that this diversity of tones affords already a great variety in the execution, which is always looked upon as being feeble and trifling, on account of the smallness of the instrument. It was not thought possible to derive much pleasure from any attempt which could be made to conquer the difficulties of so limited an instrument; because, in the extent of these octaves, there were a number of spaces which could not be filled up by the talent of the player; besides, the most simple modulation became impossible. Mr. Eulenstein has remedied that inconvenience, by joining sixteen Jew’s harps, which he tunes by placing smaller or greater quantities of sealing-wax at the extremity of the tongue. Each harp then sounds one of the notes of the gamut, diatonic or chromatic; and the performer can fill all the intervals, and pass all the tones, by changing the harp. That these mutations may not interrupt the measure, one harp must always be kept in advance, in the same manner as a good reader advances the eye, not upon the word which he pronounces, but upon that which follows.

Note 50, p. 316.--VERBAL TELEGRAPH.

This project has lately been revived; in a late number of the _Revue Encyclopédique_ there is a proposal to communicate verbal intelligence, in a few moments, to vast distances; and this not by symbols, as in the Telegraph, but in distinct articulate sounds uttered by the human voice. The plan is said to have originated with an Englishman, Mr. Dick, according to whose experiments the human voice may be made intelligible at the distance of twenty-five or thirty miles. It has been stated, in Note 44, that the celebrated Biot had ascertained that sound travels more than ten times quicker when transmitted by solid bodies, or through tubes, than when it passes through the open air; at the distance of more than half a mile the low voice of a man was distinctly heard. Father Kircher relates in some of his works, that the labourers employed in the subterranean aqueducts of Rome heard each other at the distance of several miles. The note which follows was published in the early edition of this work, before the subject attracted any notice, or any railroad had been completed. It is therefore reprinted without alteration.

Note 51, p. 316.--ELECTRICAL TELEGRAPH.

It has often occurred to the author of these pages, during his reveries, that the means of conveying intelligence with immense rapidity may be hereafter invented by the Electrician.--Should a system of railways be established throughout the country, it might lead to some expedient by which such a desideratum could be accomplished through the medium of electrical discharges. Upon this subject we have accidentally fallen upon a curious notice in Arthur Young’s Travels in France (vol. i. p. 65). “M. Lomond has made a very curious discovery in electricity; you write two or three words on a paper, he takes it with him into his room, and there turns a machine inclosed in a cylindrical case, at the top of which is an electrometer of pith balls; by means of a wire, a connexion is made with a similar cylinder and electrometer in a distant apartment, and his wife, by remarking the corresponding motions of the balls, writes down the words they indicate; from which it appears that he has formed an _Alphabet of Motion_. As the length of the conducting wire makes no difference in the effect, a correspondence might be carried on at any distance, as, for example, within or without a besieged town; or for purposes much more interesting and useful. Whatever the uses may be, the invention is beautiful.”

Note 52, p. 368.--CARRIER PIGEONS.