Jackson felt an intense wave of emotion.
He indicated the space behind him with a wave of a hand.
Dean asked, with a wave of his hands.
A wave of warmth rushed up her neck and broke over her cheeks.
On land only the grass and trees wave, but the water itself is rippled by the wind.
Another wave of dizziness washed over her.
A wave of loneliness washed over her.
But wherever it may turn there always will be the wave anticipating its movement.
"Never saw him before," I got out before a wave of nausea flooded in and I erupted again.
In the future, if you don't recognize someone, don't wave at them.
Janet gave a wave of her hand.
She indicated her face with a wave of the hand and then changed the subject.
He gave a wave but no further comment as he hurried to his Jeep and left.
All trailed by Gabriel, who paused to look up and wave at her.
"No, you go ahead," Sarah interrupted with another wave of the hand.
The hawk is aerial brother of the wave which he sails over and surveys, those his perfect air-inflated wings answering to the elemental unfledged pinions of the sea.
Lydia simply gave a dismissive wave of her hand and went inside, leaving Dean to follow.
Again the wave moved as one when the three were sighted.
In spite of the disaster of her revelation, a wave of relief passed over me.
She jumped toward the child, apparently crying out and evoking a threatening wave of the knife by Grasso.
He turned to one of the men standing around the stage office and indicated Darcie with a wave of his hand.
After I had recovered from my first experience in the water, I thought it great fun to sit on a big rock in my bathing-suit and feel wave after wave dash against the rock, sending up a shower of spray which quite covered me.
After greeting the group with a hearty wave, he proudly handed a surprised Cynthia Dean a wad of bills.
There was a sense of cold and the ooze of blood filling his boot, and a reeling wave of lightheadedness, but little pain.
Jackson drank deeply and enjoyed his venom coursing through Elisabeth, eliciting wave after wave of euphoria.
That familiar cold feeling washed over her again with a wave that was staggering.
Jennifer gave her a ta-ta wave before they entered the Dean's office.
I do try to think that he is still near, very near; but sometimes the thought that he is not here, that I shall not see him when I go to Boston,--that he is gone,--rushes over my soul like a great wave of sorrow.
"I've got them!" a woman answered excitedly and we moved in a wave to a different monitor.
They told him no, and with a wave, he was off to commiserate with his protégés.
I turned my head but he simply gave a wave of his hand.
He leaned his elbows on the wall with a wave at Rhyn.
A fresh wave of the flying mob caught him and bore him back with it.
With a wave, he left to meet with Jake Weller.
There was no verbal reply—only a returning wave of her light.
"Ah, that's always the way!" said Nesvitski with a wave of the hand.
Cynthia dropped to the couch and held the cool rag to her face as a new wave of nausea clutched her stomach.
Fred answered with a wave of his hand.
Then wrinkles ran over his face like a wave and his forehead became smooth again, he bowed his head respectfully, closed his eyes, silently let Mack enter his room before him, and closed the door himself behind him.
She gave a nervous wave, watching for his reaction and relieved when he offered a warm smile.
Bianca moved away from Talon towards the violent waves and then sat with her back to a wave as high as her waist.
Carmen poured grain into the feeders and the smell of oats and honey brought a tidal wave of goats into the barn.
Pain rippled through him and another wave of power radiated off him, turning the boulders nearby into powder.
He turned with a wave, "I'll see you later, honey bunch!"
When the ship moves in one direction there is one and the same wave ahead of it, when it turns frequently the wave ahead of it also turns frequently.
But the wave they feel to be rising does not come from the quarter they expect.
She gave an excited wave and quickened her step.
A wave of grief engulfed him and ripped through to his core, knocking the breath from him.
Another still stronger wave flowed through the crowd and reaching the front ranks carried it swaying to the very steps of the porch.
Damian's home videos played, intertwined with those of others, until a wave of power washed over her.
She had loosened her hair and her long tresses fell in a wave, over her shoulder and across her small breasts.
Dean cautioned Pumpkin to keep his hand on his wallet, but the young hiker dismissed the advice with a wave of his hand.
Ryland made a beeline for his room, and the Quincy sisters tromped up the stairs, Effie giving a three-finger wave and Claire looking as if she'd punch out the lights of anyone who got in her way.
The local vehicles that passed him invariable gave him a wave and a wide berth.
Again, as at the church in Khamovniki, a wave of general curiosity bore all the prisoners forward onto the road, and Pierre, thanks to his stature, saw over the heads of the others what so attracted their curiosity.
She looked back and with a finger wave of two chubby digits and called, "Nighty-night. Time to visit the planet Draghow!"
This didn't faze Martha in the least as she alighted from the jeep, with a wave and a thanks.
He couldn't bring himself to look down before a wave of dizziness overtook him.
A wave of unimaginable pleasure coursed through her entire body.
I didn't wave today, which means you saw him at the strip mall.
Before she could protest, Fred was off with a wave good night.
Then she added, with a dismissive wave of her hand, "That retarded child probably stole it."
Fred left with a wave and Cynthia returned to Annie Quincy's notebook.
Until that point, eminent success lay just around the corner; now, absent any leads, a wave of despair descended over me like a blanket of morning fog.
They both lost their footing at the top of one wave and tumbled into a valley, bouncing against the rubbery trough.
She opened the only door in the dead-end hallway with a wave of her armband.
Such knowledge floods the soul unseen with a soundless tidal wave of deepening thought.
He offered Dean coffee with a wave of his hand as he continued to eat.
Like the seventh and last wave that shatters a ship, that last irresistible wave burst from the rear and reached the front ranks, carrying them off their feet and engulfing them all.
Then, a wave to the dust of the retreating vehicle.
Fighting down a wave of nausea, she kneeled at the tail of the goat.
Both jumped to their feet and started around the cluster of boulders where Joseph had parked only to see the tail of Joseph Dawkins' Jeep as it bumped across the blanketing wave of wild flowers.
A wave of guilt passed over me like fog on a beach party; guilt like a pants-down lover when the husband comes home.
Here goes lumber from the Maine woods, which did not go out to sea in the last freshet, risen four dollars on the thousand because of what did go out or was split up; pine, spruce, cedar--first, second, third, and fourth qualities, so lately all of one quality, to wave over the bear, and moose, and caribou.
He was off with a jog and a wave, leaving the Deans in front of Bird Song.
She stepped down the stairs slowly and turned to wave at Mrs. Watson.
A few had been converted to apartments, but a recent wave of historical consciousness had temporarily halted the decay.
He gave a wave to Dean.
The next class of wave or oscillation detector is the magnetic detector depending upon the power of electric oscillations to affect the magnetic state of iron.
If, then, an Egyptian inscription of the XIXth dynasty had come to hand in which the names of Joseph and Moses, and the deeds of the Israelites as a subject people who finally escaped from bondage by crossing the Red Sea, were recorded in hieroglyphic characters, such a monument would have been hailed with enthusiastic delight by every champion of the Pentateuch, and a wave of supreme satisfaction would have passed over all Christendom.
curl of the wave.
This is the simplest type of antenna, a half wave dipole.
The current formed by the trochus is a gigantic vortex-ring, the down stroke of the cilia being directly outwards, brit the wave beats running round the organ in uniform succession in one direc tion.
As he started his Jeep, Ginger Dawkins, light blue sweater slung over her arm, came up the street and gave Dean an innocent wave.
Dean answered affirmatively and smiled up at Edith Shipton, giving an all-is-well wave.
They saw others on the trail only once when an elderly couple steamed by them with a wave.
Fred O'Conner, dressed for the slopes, gave a grumpy wave.
Dean climbed from her car and she was off with a wave.
"Yep. She's somewhere out west over there," Elise said with a wave of her hand towards the forest.
With a return wave, Lana set her gaze on the door to her own apartment up the stairs.
Fred dismissed the news with a wave of his hand.
Dean dismissed the comment with a wave of his hand, sorry he'd opened his mouth.
Dean smiled, gave a wave goodnight and climbed the stairs.
Fred dismissed the problem with a wave of his hand.
Fred dismissed Dean's comments with a wave of his hand.
One minute he'd be drinking in the beauty of the countryside and the next feeling a wave of anxiety, realizing what had begun as a mild suspicion was close to culminating in a face-to-face confrontation with Jeffrey Byrne.
When the road straightened once more, he heard a noise behind him and a dozen daredevils in the tuck position sped on by him with a wave and a rush of air.
He felt a wave of apprehension and accelerated heart beat as the door opened.
She paused and smiled up at him, one eye almost covered by a wave of gray hair.
Anger washed over her in a bold wave.
She returned his wave without slowing down.
She battled a wave of panic and felt drained as the feeling abated.
She'd given it to Talia before she left then reclaimed it after the first wave of the Schism ripped through the Immortal world.
Then the first wave of the Schism hit.
Rather than reply, he released a wave of power that knocked over guardsmen and trees alike.
He was swallowed by the dark forest before she could return the wave.
A wave of anger came out of nowhere, surging through her veins and washing the resentment to the surface of her consciousness.
Engulfed by a wave of homesickness, she turned away, shrugging off the unexpected emotion.
A wave of homesickness engulfed her, and she struggled back to the firm ground of reality.
She glanced down at her wrinkled nightclothes and felt a scarlet wave surge up her neck.
"I've been waiting –" She rose on her tiptoes to wave at Xander even as another woman shoved her back.
If the particles were away, the wave would pass on unbroken and no light would be emitted laterally.
The element of area being 22rr 2 sin 04,, we have f:2 l 2x r2 si n 2 d ?=gam, r so that the energy emitted from T is represented by 87r3 (D, - D) 2 T2 (9) D2 x4' on such a scale that the energy of the primary wave is unity per unit of wave-front area.
Since there is no waste of energy upon the whole, this represents the loss of energy in the primary wave.
Thus he approximates to the wave theory of light, though he supposed that the transmission of light was instantaneous.
The following branches have especially felt his influence: - chemical physics, capillarity and viscosity, theory of gases, flow of liquids, photography, optics, colour vision, wave theory, electric and magnetic problems, electrical measurements, elasticity, sound and hydrodynamics.
These striking successes caused a wave of revolt to spread through Holland, Zeeland, Gelderland, Utrecht and Friesland.
The tidal wave of the Southern Ocean, which sweeps uninterruptedly round the globe from east to west, generates a secondary wave between Africa and South America, which travels north at a rate dependent only on the depth of the ocean.
With this " free " wave is combined a " forced " wave, generated, by the direct action of the sun and moon, within the Atlantic area itself.
In depths beyond the reach of wave motion, and apart from suspension across a submarine gully, which will sooner or later result in a rupture of the cable, the most frequent cause of interruption is seismic or other shifting of the ocean bed, while in shallower waters and near the shore the dragging of anchors or 40 fishing trawls has been mostly responsible.
of a condenser produces an electric spark which under proper conditions creates an effect propagated out into space as an electric wave.
He employed as a detector of this wave a simple, nearly closed circuit of wire called a Hertz resonator, but it was subsequently discovered that the metallic microphone of D.
On creating an electric spark or wave in the neighbourhood of the tube the resistance suddenly falls to a few ohms and the cell sends a current through it.
But, as Branly showed, it is not universally true that the action of an electric wave is to reduce the resistance of a tube of powdered metal or cause the particles to cohere.
This form of electric wave detector proved itself to be far more certain in operation and sensitive than anything previously invented.
The magnetic and electric forces are directed alternately in one direction and the other, and at distances which are called multiples of a wave length the force is in the same direction at the same time, but in the case of damped waves h.as not quite the same intensity.
Fleming's Electric Wave Telegraphy, by permission of Longmans, Green & Co.
' For a more complete account of the nature of an electric wave the reader is referred to Hertz's Electric Waves, and to the article Electric Wave.
See also The Principles of Electric Wave Telegraphy, by J.
- Marconi Sensitive Metallic Filings Tube or Electric Wave Detector.
This periodic distribution in time and space constitutes an electric wave proceeding outwards in all directions from the sending antenna.
He thus produced in 1896 for the first time an operative apparatus of electric wave telegraphy.
Marconi's successes and the demonstrations he had given of the thoroughly practical character of this system of electric wave telegraphy stimulated other inventors to enter the same field of labour, whilst theorists began to study carefully the nature of the physical operations involved.
We now consider the more recent appliances for electric wave telegraphy under the two divisions of transmitting and receiving apparatus.
This creates rapid variations in electric and magnetic force round the antenna and detaches energy from it in the form of an electric wave.
The whole process is exactly analogous to the operation by which a violin string or organ pipe creates an air or sound wave.
In many cases additional condensers or inductance coils are inserted in various places so that the arrangement is somewhat disguised, but by far the larger part of the electric wave wireless telegraphy in 1907 was effected by transmitters having antennae either inductively or directly coupled to a closed condenser circuit containing a spark gap.
When electric oscillations are set up in an open or closed electric circuit having capacity and inductance, and left to themselves, they die away in amplitude, either because they dissipate their energy as heat in overcoming the resistance of the circuit, or because they radiate it by imparting wave motion to the surrounding ether.
It was then found that when electric waves fell on the antenna a sound was heard in the telephone as each wave train passed over it, so that if the wave trains endured for a longer or shorter time the sound in the telephone was of corresponding duration.
This device was converted into an electric wave detector as follows :-The mercury-steel junction was acted upon by the electromotive force of a shunted single cell and a siphon recorder was inserted in series.
An innumerable number of forms of coherer or wave detector depending upon the change in resistance produced at a loose or imperfect contact have been devised.
Fleming, The Principles of Electric Wave Telegraphy and Telephony, p. 416, 2nd ed.
Rutherford used this detector to make evident the passage of an electric or Hertzian wave for half a mile across Cambridge, England.
Wilson constructed various forms of electric wave detector depending on this same principle.
In 1902 Marconi invented two forms of magnetic detector, one of which he developed into an electric wave detector of extraordinary delicacy and utility.
A third class of electric wave detector depends upon the power of electric oscillations to annul the electrolytic polarization of electrodes of small surface immersed in an electrolyte.
A fourth class of electric wave detector comprises the thermal detectors which operate in virtue of the fact that electric oscillations create heat in a fine wire through which they pass.
Such a bolometer receiver has been used by C. Tissot (Comptes rendus, 1904, 137, p. 846) and others as a receiver in electric wave telegraphy.
When electric oscillations are set up in these two classes of electric radiators, the first class send out a highly damped wave train and the second a feeble damped wave train provided that they have sufficient capacity or energy storage and low resistance.
Slaby in Berlin shortly afterwards made a similar exhibition of syntonic electric wave telegraphy' O.
Lodge had previously described in 1897 a syntonic system of electric wave telegraphy, but it had not been publicly seen in operation prior to the exhibitions of Marconi and Slaby.'
wave trains; but, although other patentees have suggested the same plan, the author is not aware that any success has attended its use in practice.
Very briefly stated, his method consists in sending out a group of wave trains at certain irregular but assigned intervals of time to constitute the simplest signal equivalent to a dot in the Morse code, and a sequence of such trains, say three following one another, to constitute the dash on the Morse code.
At this stage it may be convenient to outline the progress of electric wave telegraphy since 1899.
Braun showed that oscillations suitable for the purposes of electric wave creation in wireless telegraphy could be set up in a circuit consisting of a Leyden jar or jars, a spark gap and an inductive circuit, and communicated to an antenna either by inductive or direct coupling (Brit.
All of them couple the transmitting antenna directly or inductively to a capacity-inductive circuit serving as a storage of energy, and all of them create thereby electric waves of the same type moving over the earth's surface with the magnetic force of the wave parallel to it.
From and after that time the British Admiralty and the navies of other countries began to give great attention to the development of electric wave telegraphy.
200 m., and he considered that the time had come for a serious attempt to be made to communicate across the Atlantic. A site for a first Transatlantic electric wave power station was secured at Poldhu, near Mullion in south Cornwall, by the Marconi Company, and plans arranged for an installation.
The special electrical engineering arrangements employed at the outset for this first electric wave power station required to create the oscillations of the desired power were designed for Marconi by J.
long upheld by a box kite, and, employing a sensitive coherer and telephone as a receiver, he was able, on December 12, 1901, to hear " S " signals on the Morse code, consisting of three dots, which he had arranged should be sent out from Poldhu at stated hours, according to a preconcerted programme, so as to leave no doubt they were electric wave signals sent across the Atlantic and not accidental atmospheric electric disturbances.
This result created a great sensation, and proved that Transatlantic electric wave telegraphy was quite feasible and not inhibited by distance, or by the earth's curvature even over an arc of a great circle 3000 m.
In 1904 a regular system of communication of press news and private messages from the Poldhu and Cape Breton stations to Atlantic liners in mid-Atlantic was inaugurated, and daily newspapers were thenceforth printed on board these vessels, news being supplied to them daily by electric wave telegraphy.
A problem of great importance in connexion with electric wave telegraphy is that of limiting the radiation to certain directions.
Fleming, The Principles of Electric Wave Telegraphy (London, 1906), chap. vii.; also Cantor Lectures on Hertzian wave telegraphy, Lecture iv., Journ.
The process of reflection in the case of a wave motion involves the condition that the wave-length shall be small compared with the dimensions of the mirror, and hence the attempt to reflect and converge electric waves loon ft.
Fleming, The Principles of Electric Wave Telegraphy, 1906, p. 73.
The scientific study of electric wave telegraphy has necessitated the introduction of many new processes and methods of electrical measurement.
In all cases of wave motion the wave-length is connected with the velocity of propagation of the radiation by the relation v=nX, where n is the frequency of the oscillations and X is the wave-length.
Instruments for doing this are called wave meters and are of two kinds, open circuit and closed circuit.
2 In Donitz's wave meter a condenser of variable capacity is associated with inductance coils of various sizes, and the wave meter is placed near the antenna so that its inductance coils have induced currents created in them.
An immense mass of information has been gathered on the scientific processes which are involved in electric wave telegraphy.
Starting from an observation of Marconi's, a number of interesting facts have been accumulated on the absorbing effect of sunlight on the propagation of long Hertzian waves through space, and on the disturbing effects of atmospheric electricity as well as upon the influence of earth curvature and obstacles of various kinds interposed in the line between the sending and transmitting stations.4 Electric wave telegraphy has revolutionized our means of communication from place to place on the surface of the earth, making it possible to communicate instantly and certainly between places separated by several thousand miles, whilst The Electrician, 1904, 5 2, p. 407, or German Pat.
It is now generally recognized that Hertzian wave telegraphy, or radio-telegraphy, as it is sometimes called, has a special field of operations of its own, and that the anticipations which were at one time excited by uninformed persons that it would speedily annihilate all telegraphy conducted with wires have been dispersed by experience.
Fleming, Hertzian Wave Telegraphy (1905); id., The Principles of Electric Wave Telegraphy and Telephony (2nd ed., 1910); J.
Pupin showed that by placing inductance coils in circuit, at distances apart of less than half the length of the shortest component wave to be transmitted, a non-uniform conductor could be made approximately equal to a uniform conductor.
It would follow, on the other hand, that what is called Oscan represented the language of the invading Sabines (more correctly Safines), whose racial affinities would seem to be of a distinctly more northern cast, and to mark them, like the Dorians or Achaeans in Greece, as an early wave of the invaders who more than once in later history havevitally influenced the fortunes of the tempting southern land into which they forced their way.
In the case of Messina the horror of the situation was heightened by a tidal wave.
Before this wave of thought, H.
The colouring of the steppe changes as if by magic, and only the silvery plumes of the steppe-grass (Stipa pennata) wave in the wind, tinting the steppe a bright yellow.
Byron's description, "[The] immemorial wood Rooted where once the Adrian wave flowed o'er," is probably true; but there is no evidence that it was in historic time that this change took place.
These ancient states began to decline in the 7th century B.e., and on their ruins rose the Persian empire, which with various political metamorphoses continued to be an important power till the 7th century A.D., after which all western Asia was overwhelmed by the Moslem wave, and old landmarks and kingdoms were obliterated.
Napcleon was now able by degrees to dispense with all republican forms (the last to go was the Republican Calendar, which ceased on the 1st of January 1806), and the scene at the coronation in Notre Dame on the 2nd of December 1804 was frankly imperial in splendour and in the egotism which led Napoleon to wave aside the pope, Pius VII., at the supreme moment and crown himself.
Akhenaton at Tell el-Amarna; while in the Aegean area itself we have abundant evidence of a great wave of Egyptian influence beginning with this same Dynasty.
To this wave were owed in all probability the Nilotic scenes depicted on the Mycenae daggers, on frescoes of Hagia Triada and Cnossus, on pottery of Zakro, on the shell-relief of Phaestus, &c.; and also many forms and fabrics, e.g.
Many of these tribes have retained their pristine paganism, but many others it is certain have adopted the Mahommedan religion and have been assimilated by the subsequent and stronger wave of Sumatran immigrants.
of the Kachins or Chingpaw were the Indo-Chinese race who, before the beginnings of history, but after the Mon-Annam wave had covered Indo-China, forsook their home in western China to pour over the region where Tibet, Assam, Burma and China converge, and that the Chingpaw are the residue left round the headquarters of the Irrawaddy and the Chindwin after those branches, destined to become the Tibetans, the Nagas, the Burmans and the Kuki Chins, had gone westwards and southwards.
For the subjects of this general heading see the articles Mechanics; Dynamics, Analytical; Gyroscope; Harmonic Analysis; Wave; HYDROMechanics; Elasticity; Motion, Laws Of; Energy; Energetics; Astronomy (Celestial Mechanics); Tide.
"On the morrow of the Sabbath" a wave offering of a sheaf of barley was to be made.
On the morrow after the sabbath a wave offering and also a burnt offering of the he-lamb (with the corresponding meal and drink offering).
The original church of St Mary's, at the mouth of the river, was swept away by a tidal wave in 1607: Wordsworth took this as a subject for a sonnet.
The present city is half a mile north of the site of the old town, which was destroyed by an earthquake and tidal wave in 1746.
In spring the traveller crosses a sea of grass above which the flowers of the paeony, aconite, Orobus, Carallic, Saussurea and the like wave 4 or 5 ft.
This resolution of the original wave is the well-known "Principle of Huygens," and by its means he was enabled to prove the fundamental laws of optics, and to assign the correct construction for the direction of the extraordinary ray in uniaxial crystals.
The wave of morphological speculation, with its outcome of new systems and new theories of classification.
The wave motion due to any element of the surface is called a secondary wave, and in estimating the total effect regard must be paid to the phases as well as the amplitudes of the components.
It is usually convenient to choose as the surface of resolution a wave front, i.e.
We have seen that the problem before us is independent of the law of the secondary wave as regards obliquity; but the result of the integration necessarily involves the law of the intensity and phase of a secondary wave as a function of r, the distance from the origin.
Journ., 18 43, 3, p. 46), determine the law of the secondary wave, by comparing the result of the integration with that obtained by supposing the primary wave to pass on to P without resolution.
Now as to the phase of the secondary wave, it might appear natural to suppose that it starts from any point Q with the phase of the primary wave, so that on arrival at P, it is retarded by the amount corresponding to QP. But a little consideration will prove that in that case the series of secondary waves could not reconstitute the primary wave.
It is accordingly necessary to suppose that the secondary waves start with a phase one-quarter of a period in advance of that of the primary wave at the surface of resolution.
It may be well therefore to remember that precisely these laws apply to a secondary wave of sound, which can be investigated upon the strictest mechanical principles.
If the primary wave at 0 be cos kat, the effect of the secondary wave proceeding from the element dS at Q is dS 1 dS - p cos k(at - p+ 4 A) = - -- sin k(at - p).
In order to obtain the effect of the primary wave, as, retarded by traversing the distance r, viz.
According to the assumed law of the secondary wave, the result must actually depend upon the precise radius of the outer boundary of the region of integration, supposed to be exactly circular.
When the primary wave is plane, the area of the first Fresnel zone is 7rXr, and, since the secondary waves vary as r 1, the intensity is independent of r, as of course it should be.
If, however, the primary wave be spherical, and of radius a at the wave-front of resolution, then we kno* that at a distance r further on the amplitude of the primary wave will be diminished in the ratio a:(r+a).
when the secondary wave of least retardation is unobstructed, or when a ray passes through the point under consideration.
a secondary wave suitable when the primary wave is undisturbed, with mere limitation of the integration to the transparent parts of the screen.
Taking co-ordinates in the plane of the screen with the centre of the wave as origin, let us represent M by, n, and P (where dS is situated) by x, y, z.
15, p. 315) to determine the absolute intensity of a secondary wave, may be at once effected by means of the known formula isin 2 u f sin u du = du =7-.
This indefiniteness of images is sometimes said to be due to diffraction by the edge of the aperture, and proposals have even been made for curing it by causing the transition between the interrupted and transmitted parts of the primary wave to be less abrupt.
The phase of the resultant amplitude is the same as that due to the central secondary wave, and the discrepancies of phase among the components reduce the amplitude in the proportion l ` dri): 3?
The aberration is here unsymmetrical, the wave being in advance of its proper place in one half of the aperture, but behind in the other half.
The formula expressing the optical power of prismatic spectroscopes may readily be investigated upon the principles of the wave theory.
The dark lines which separate the bands are the places at which the phases of the secondary wave range over an integral number of periods.
We have hitherto supposed that the light is incident perpen 1 The last sentence is repeated from the writer's article " Wave Theory " in the 9th edition of this work, but A.
whether it was the cutting edge or the back of a razor - made no material difference, and was thus led to the conclusion that the explanation of these phenomena requires nothing more than the application of Huygens's principle to the unobstructed parts of the wave.
When, in order to apply Huygens's principle, the wave is supposed to be broken up, the phase is the same at every element of the surface of resolution which lies upon a line perpendicular to the plane of reference, and thus the effect of the whole line, or rather infinitesimal strip, is related in a constant manner to that of the element which lies O in the plane of reference, and may be considered to be represented thereby.
Taking as the standard phase that of the secondary wave from A, we may represent the effect of PQ by cos 27r (_) .ds, where, l = BP - AP is the retardation at B of the wave from P relatively to that from A.
To assume a cylindrical form of primary wave would be justifiable only when there is synchronism among the secondary waves issuing from the various centres.
For a point Q outside the shadow the integration extends over more than half the primary wave.
The latter is the intensity due to the uninterrupted wave.
18) the centre of the curve 0 is to be considered to correspond to that point C of the primary wave-front which lies nearest to P. The operative part, or parts, of the curve are of course those which represent the unobstructed portions of the primary wave.
At the point 0 the intensity is one-quarter of that of the entire wave, and after this point is passed, that is, when we have entered the geometrical shadow, the intensity falls off gradually to zero, without fluctuations.
But, without entering upon matters of this kind, we may inquire in what manner a primary wave may be resolved into elementary secondary waves, and in particular as to the law of intensity and polarization in a secondary wave as dependent upon its direction of propagation, and upon the character as regards polarization of the primary wave.
It is then verified that, after integration with respect to dS, (6) gives the same disturbance as if the primary wave had been supposed to pass on unbroken.
The factor (I -cos 0) shows in what manner the secondary disturbance depends upon the direction in which it is propagated with respect to the front of the primary wave.
If, as suffices for all practical purposes, we limit the application of the formulae to points in advance of the plane at which the wave is supposed to be broken up, we may use simpler methods of resolution than that above considered.
The conception of the lamina leads immediately to two schemes, according to which a primary wave may be supposed to be broken up. In the first of these the element dS, the effect of which is to be estimated, is supposed to execute its actual motion, while every other element of the plane lamina is maintained at rest.
When the secondary disturbance thus obtained is integrated with respect to dS over the entire plane of the lamina, the result is necessarily the same as would have been obtained had the primary wave been supposed to pass on without resolution, for this is precisely the motion generated when every element of the lamina vibrates with a common motion, equal to that attributed to dS.
If, instead of supposing the motion at dS to be that of the primary wave, and to be zero elsewhere, we suppose the force operative over the element dS of the lamina to be that corresponding to the primary wave, and to vanish elsewhere, we obtain a secondary wave following quite a different law.
In this case the motion in different directions varies as cos°, vanishing at right angles to the direction of propagation of the primary wave.
In order to apply these ideas to the investigation of the secondary wave of light, we require the solution of a problem, first treated by Stokes, viz.
The intensity of light is, however, more usually expressed in terms of the actual displacement in the plane of the wave.
We will now apply (18) to the investigation of a law of secondary disturbance, when a primary wave = sin (nt - kx) (19) is supposed to be broken up in passing the plane x = o.
The occurrence of factors such as sin 4), or 2 (1cos 0), in the expression of the secondary wave has no influence upon the result of the integration, the effects of all the elements for which the factors differ appreciably from unity being destroyed by mutual interference.
A wave of military enthusiasm arose throughout the empire, and as the formation of a seventh division practically drained the mother-country of trained men, a scheme for the employment of amateur soldiers was formulated, resulting in the despatch of Imperial Yeomanry and Volunteer contingents, which proved one of the most striking features of the South African campaign.
The geometrical theory can afford no explanation of these coloured bands, and it has been shown that the complete phenomenon of the rainbow is to be sought for in the conceptions of the wave theory of light.
In 1868 the town was nearly destroyed by an earthquake, in 1875 by fire, and again in 1877 by earthquakes, a fire and a tidal wave.
The explosive wave from the dry guncotton primer is in fact better responded to by the wet compressed material than the dry, and its detonation is somewhat sharper than that of the dry.
It is not necessary for the blocks of wet guncotton to be actually in contact if they be under water, and the peculiar explosive wave can also be conveyed a little distance by a piece of metal such as a railway rail.
It is strange that so little interest has been taken in a craft in which for some thirty years England surpassed all competitors, creating a wave of fashion which influenced the glass industry throughout the whole of Europe.
Nanak seems to have been produced by the same cyclic wave of reformation as fourteen years later gave Martin Luther to Europe.
The branch of hydrodynamics which discusses wave motion in a liquid or gas is given now in the articles Sound and Wave; while the influence of viscosity is considered under Hydraulics.
The estuary or bay is funnel-shaped, and its configuration produces at spring tides a " bore " or tidal wave, which at its maximum reaches a height of 15 to 20 ft.
Great damage was done by a seismic wave following the shock.
The town was overwhelmed by a vast wave, which rose 80 ft.; and the shocks continued until the following February.
It is situated on the right bank of the Seine, the tidal wave of which (mascaret) can be well seen at this point.
(2) Tidal wave killed thousands of people.
The development of Japanese painting may be divided into the following six periods, each signalized by a wave of progress.
The native artist who crested the first great wave of Japanese painting was a court noble named Kos no Kanaoka, living under the patronage of the emperor Seiwa ~ mi (850859) and his successors down to about the end of J~~d the 9th century, in the midst of a period of peace and culture.
The manifold plate is then heavily punched from one side, so that the opposite face protrudes in broken blisters, which are then hammered down until each becomes a centre of wave propagation.
The earthquake occurred early in the morning of December 28, and so far as Messina was concerned the damage was done chiefly by the shock and by the fires which broke out afterwards; the seismic wave which followed was comparatively innocuous.
In mechanics, the amplitude of a wave is the maximum ordinate.
He was in the act of issuing his orders when a psychological wave swept through the fighting-line, and the men rose and rushed the village at the point of the bayonet.
This was stopped almost entirely by the Prussian artillery fire; but the news of its coming spread through the stragglers in the ravine south of the great road, and a wave of panic again swept through the mass, many thousands bolting right upon the front of their own batteries, thus masking their fire at the most critical moment, and something like a crisis in the battle arose.
But as things are the watersurface is broken by land, and the mean density of the substance of the land is 2 6 times as great as that of sea-water, so that the gravitational attraction of the land must necessarily cause a heaping up of the sea around the coasts, forming what has been called the continental wave, and leaving the sea-level lower in mid-ocean.
Pure calcareous sand and calcareous mud are formed by wave action on the shores of coral islands where the only material available is coral and the accompanying calcareous algae, crustacea, molluscs and other organisms secreting carbonate of lime.
We are still ignorant of the depth to.which the annual temperature wave penetrates in the open ocean, but observations in the Mediterranean enable us to form some opinion on the matter.
blue lines (of wave length 4555 and 4593) in their flame spectrum, but these are not present in the spark spectrum.
The observation that acetylene can be resolved into its constituents by detonation is due to Berthelot, who started an explosive wave in it by firing a charge of oï¿½i gram of mercury fulminate.
It has since been shown, however, that unless the gas is at a pressure of more than two atmospheres this wave soon dies out, and the decomposition is only propagated a few inches from the detonator.
This wave of enthusiasm spread from Northampton, Mass., till it swept New England.
Between these cyclonic storms come areas of high pressure, or anticyclones, with dry cool air in summer, and dry cold air in winter, sometimes with such decided changes in temperature as to merit the name cold wave.
As the anti-Masonic wave subsided its leaders and most of its adherents found a place in the newly organized Whig party, which was powerful enough in New York to elect William H.
But the socialistic labour wave of later years had not yet gathered strength.
As sound arises in general from vibrating bodies, as it takes time to travel, and as the medium which carries it does not on the whole travel forward, but subsides into its original position when the sound has passed, we are forced to conclude that the disturbance is of the wave kind, We can at once gather some idea of the nature of sound waves in air by considering how they are produced by a bell.
If a second card with a narrow slit in it is held in front of the first, the slit running from the centre outwards, the wave motion is still more evident.
If the figure be photographed as a lantern slide which is mounted so as to turn round, the wave motion is excellently shown on the screen, the compressions and extensions being represented by the crowding in and opening out of the lines.
For instance, if a rope is fixed at one end and held in the hand at the other end, a transverse jerk by the hand will travel as a transverse wave along the rope.
If each wave travels out from the source with velocity U the n waves emitted in one second must occupy a length U and therefore U = nX.
4 be the displacement diagram of a wave travelling from left to right.
If a wave travels on without alteration the travelling may be represented by pushing on the displacement curve.
Let the wave Aqbtc (fig.
To find the relation of the velocity to displacement and pressure we shall express the fact that the wave travels on carrying all its conditions with it, so that the displacement now at M will arrive at N while the wave travels over MN.
Let U be the velocity of the wave and let u be the velocity of the particle originally at N.
In the time dt which the wave takes to travel over MN the particle displacement at N changes by QR, and QR= - udt, so that QR/MN = - u/U.
Generally, if any condition in the wave is carried forward unchanged with velocity U, the change of 4 at a given point in time dt is equal to the change of as we go back along the curve a distance dx = Udt at the beginning of dt.
We can only conclude that it depends on wave form, a conclusion fully borne out by investigation.
Whatever the form of a wave, we could always force it to travel on with that form unchanged, and with any velocity we chose, if we could apply any " external " force we liked to each particle, in addition to the " internal " force called into play by the compressions or extensions.
If the velocity U is so chosen that E - poU 2 = o, then X = o, or the wave travels on through the action of the internal forces only, unchanged in form and with velocity U = (E/p).
(6) The pressure X is introduced in order to show that a wave can be propagated unchanged in form.
If, however, we put on external forces of the required type X it is obvious that any wave can be propagated with any velocity, and our investigation shows that when U has the value in (6) then and only then X is zero everywhere, and the wave will be propagated with that velocity when once set going.
It implies that the different parts of a wave move on at different rates, so that its form must change.
Probably there is a breakdown of the wave somewhat like the breaking of a water-wave when the crest gains on the next trough.
This gives maximum u=about 8 cm./sec., which would not seriously change the form of the wave in a few wavelengths.
We shall show that if we sum these up for a whole wave the potential energy is equal to the kinetic energy.
The kinetic energy per cubic centimetre is 2 pu t, where is the density and u is the velocity of disturbance due to the passage of the wave.
The term Pv/V added up for a complete wave vanishes, for P/V is constant and Zv=o, since on the whole the compression equals the extension.
When the wave travelled to the receiver it pushed back the disk from the contact-piece, and this break, too, was recorded.
When a wave of sound meets a surface separating two media it is in part reflected, travelling back from the surface into the first medium again with the velocity with which it approached.
When a wave of sound travelling through one medium meets a second medium of a different kind, the vibrations of its own particles are communicated to the particles of the new medium, so that a wave is excited in the latter, and is propagated through it with a velocity dependent on the density and elasticity of the second medium, and therefore differing in general from the previous velocity.
The direction, too, in which the new wave travels is different from the previous one.
the direction of the wave in the first medium), and the normal to the surface separating the two media, at the point in which the incident ray meets it; (2) The sine of the angle between the normal and the incident ray bears to the sine of the angle between the normal and the refracted ray a ratio which is constant for the same pair of media.
As with light the ratio involved in the second law is always equal to the ratio of the velocity of the wave in the first medium to the velocity in the second; in other words, the sines of the angles in question are directly proportional to the velocities.
If a wave front is in a given position, as a 1 (fig.
Consequently a wave front such as b 1 tends to turn upwards, as shown in the successive positions b 2, 3 and 4.
The velocity of any part of a wave front relative to the ground will be the normal velocity of sound + the velocity of the wind at that point.
But if the wind is against the sound the velocity of a point of the wave front is the normal velocity-the wind velocity at the point, and so decreases as we rise.
A short impulsive wave travels towards the fence, and each rail as it is reached by the wave becomes the centre of a new secondary wave sent out all round, or at any rate on the front side of the fence.
At the instant that the original wave reaches F the wave from E has travelled to a circle of radius very nearly equal to EF-not quite, as S is not quite in the plane of the rails.
The wave from D has travelled to a circle of radius nearly equal to DF, that from C to a circle of radius nearly CF, and so on.
The engine follows up any wave that it has sent forward, and so crowds up the succeeding waves into a less distance than if it remained at rest.
It draws off from any wave it has sent backward and so spreads the succeeding waves over a longer distance than if it had remained at rest.
But through the wind velocity the first wave is carried to a distance U + w from S, while through the motion of the source the last wave is a distance u from S.
If he were at rest, it would be the waves in length U + w, for the wave passing him at the beginning of a second would be so far distant at the end of the second.
The simplest form of wave, so far as our sensation goes - that is, the one giving rise to a pure tone - is, we have every reason to suppose, one in which the displacement is represented by a harmonic curve or a curve of sines, y=a sin m(x - e).
For the superposition of these trains will give a stationary wave between A H A (16) Y which is an equation characteristic of simple harmonic motion.
at the distance of the listener, and thence from the energy in a wave, found above, to determine the amplitude.
28 are represented the stationary wave systems of the first four modes, and any of the succeeding ones are easily drawn.
The stationary wave method regards the vibration in the pipe as due to a series of waves travelling to the end and being there reflected back down the pipe.
29 are represented the stationary wave systems of the first four modes.
The stationary wave system adjusts itself so that its motion agrees with that of the sounder, which is therefore not exactly at a node.
& 'm =21rnapU, for in the stationary wave system the pressure change and the amplitude are both double those in either train, so that the same relation holds.
34 the stationary wave systems of the first four modes are represented.
When two trains of sound waves travel through the same medium, each particle of the air, being simultaneously affected by the disturbances due to the different waves, moves in a different manner than it would if only acted on by each wave singly.
We shall then obviously be led to the following results: If the two waves are of equal length X, and are in the same phase (that is, each producing at any given moment the same state of motion in the air particles), their combined effect is equivalent to that of a wave of the same length X, but by 2 which the excursions of the particles are increased, being the sum of those due to the two component waves respectively, as in fig.
If the two interfering waves, being still of same length X, be in opposite phases, or sõ that one is in advance of the other by 2X, and consequently one produces in the air the opposite state of motion to the other, then the resultant wave is one of the same length X, but the excursions of the particles are decreased, being the difference between those due to the component waves as in fig.
The third mode of production of combination tones, the production in the medium itself, follows from the varying velocity of different parts of the wave, as investigated at the beginning of this article.
A grand campaign of agitation on the part of the Russian Count Bobrinsky, whose watch-word was that the Russian banner must wave over the Carpathians, though winked at by the Polish governor, led to a great political trial (Dec. 29 1913) for high treason of 180 Ruthenians who had been seduced by this agitator.
The commercial treaty of 1786 between Great Britain and France has already been referred to as making a breach in the restrictive system of the 18th century; and in the early years of the French Revolution a similar wave of liberal policy is to be seen.
His SOD, George Cabot Lodge (1873-1909), also became known as an author, with The Song of the Wave (1898), Poems, 1899-1902 (1902), The Great Adventure (1905), Cain: a Drama (1904), Herakles (1908) and other verse.
But with these insignificant exceptions it holds true that, after the sceptical wave marked by the Sophists, scepticism does not reappear till after the exhaustion of the Socratic impulse in Aristotle.
The town occupies a narrow beach between the sea and bluffs, and was greatly damaged by an earthquake and tidal wave in 1877.
A wave of intense religious feeling passes over the land and finds its expression, according to the ordinary law of oriental life, in the formation of a sort of enthusiastic religious order.
In Acapulco a tidal wave followed the shock.
Thus, if one molecule is disturbed from its mean position, it communicates the disturbance to its neighbours, and so a wave is propagated.
Thus the ether within the dispersive medium is loaded with molecules which are forced to perform oscillations of the same period as that of the transmitted wave.
The fundamental assumption is that the medium contains positively and negatively charged ions or electrons which are acted on by the periodic electric forces which occur in wave propagation on Maxwell's theory.
One of the best indications of actual winter weather, as apart from the arrival of winter by the calendar, is the development of cyclonic disturbances of such strength that the change frcm their warm, sirocco-like southerly inflow hi front of their centre, to the cold wave of their rear produces lion-periodic temperature changes strong enough to overcome the weakened diurnal temperature changes of the cold season, a relation which practically never occurs in summer time.
At extremely rare intervals the thermometer has fallen below zero, as was the case in the remarkable cold wave of the lath-13th of February 1899, when an absolute minimum of 17° was registered at Valley Head.
The great earthquake of 1868, followed by a tidal wave, nearly destroyed the town and shipping.
The limitation of power is introduced as in all optical instruments, by the finiteness of the length of a wave of light which causes the image of an indefinitely narrow slit to spread out over a finite width in the focal plane of the observing telescope.
The problem, which, in the opinion of the present writer, is the one of interest and has more or less definitely been in the minds of those who have discussed the subject, is whether the type of wave sent out by a molecule only depends on the internal energy of that molecule, or on other considerations such as the mode of excitement.
According to present ideas, the wave originates in a disturbance of electrons within the molecules.
In that case Au/V or the half width of the band measured in wave lengths would be .105 A, or, for the red line, the half width would be 0.044 A.
The efforts which were consequently made in the early days of spectroscopy to discover some numerical relationship between the different wave lengths of the lines belonging to the same spectrum rather disregard the fact that even in acoustics the relationship of integer numbers holds only in special and very simple cases.
Balmer, who showed that the four hydrogen lines in the visible part of the spectrum may be represented by the equation n = A(i - 4/s2), where n is the reciprocal of the wave-length and therefore proportional to the wave frequency, and s successively takes the values 3, 4, 5, 6.
It would therefore seem to be more appropriate to replace 1 - K- 1 by (2 - I)1112, where j s is the refractive index; but this expression involves the wave propagation for periods coinciding with free periods of the molecules.
Save in some parts of Germany, where the influence of Luther saved the churches from wreck, an iconoclastic wave spread over the greater part of Western Europe, wherever the " new religion " prevailed; everywhere churches were cleared of images and reduced to the state of those described by William Harrison in his Description of England (1570), only the " pictures in glass " being suffered in some cases to survive for a while " by reason of the extreme cost of replacing them."
Yet the wave of reaction which soon overwhelmed the freer tendencies of the first reformers, brought back the old view until the revival of biblical criticism more than a century ago.
The alignment of marine shafting, changing with every passing wave, is an extreme example.
A great wave of secularity rolled over the Church, engulfing the religious orders with the rest; love waxed cold, fervour languished; learning declined, discipline was relaxed, bitter rivalries broke out, especially between Franciscans and Dominicans.
The form of the wave was also changed.
For instance, the velocity of propagation of a wave having a period of a day is nearly twenty times as great as that of a wave with a period of one year; but on the other hand the penetration of the diurnal wave is nearly twenty times less, and the shorter waves die out more rapidly.
A Simple-Harmonic or Sine Wave is the only kind which is propagated without change of form.
The wave at a depth x is represented analytically by the equation 0 - 0 0 = Ae mx sin (21rnt - mx).
5 are drawn for a particular case, but they apply equally to the propagation of a simple-harmonic wave of any period in any substance changing only the scale on which they are drawn.
The diffusivity can be deduced from observations at different depths x' and x", by observing the ratio of the amplitudes, which is (x '- x ") for a simple-harmonic wave.
In any case results deduced from the annual wave must be expected to vary in different years according to the distribution of the rainfall, as the values represent averages depending chiefly on the diffusion of heat by percolating water.
The following are a few typical values for sand or gravel deduced from the annual wave in different localities: - [[Table Ii]].
In the wave of successful rebellion, except at Khartum, few of the Egyptian garrisons were killed when the posts fell, long residence and local family ties rendering easy their assimilation in the ranks of the Mahdists.
It may be questioned whether it was due to a wave of enthusiasm amongst the priests and people, leading them to rededicate the monuments in the name of their deliverer, or a somewhat insane desire of the king to perpetuate his own memory in a singularly unfortunate manner.
The disturbance travels as a wave of contraction, and the whole extent of the wave-like disturbance measures in ordinary muscles much more than the whole length of any single muscle fibre.
The wave of change (nervous impulse) induced in a neuron by advent of a stimulus is after all only a sudden augmentation of an activity continuous within the neuron - a transient accentuation of one (the disintegrative) phase of the metabolism inherent in and inseparable from its life.
` Hang it lower,' said the king, beckoning his groom with a wave of the finger; ` lower, that they may not have to hurt their necks about it.'
But in every country alike the wave of viking conquest now begins to recede.
"Let us make," said Gaiseric, "for the dwellings of the men with whom God is angry," and he left the conduct of his marauding ships to wind and wave.
The seismic' wave was also his work; the destruction of Helice in Achaea by such a wave (373 B.C.) was attributed to his wrath (Strabo viii.
The maharaj rana of Dholpur belongs to the clan of Bamraolia Jats, who are believed to have formed a portion of the IndoScythian wave of invasion which swept over northern India about A.D.
Gallium is best detected by means of its spark spectrum, which gives two violet lines of wave length 4171 and 4031.
The suggestion was made, and seems to be the true explanation, that what was actually witnessed was the wave of light due to the outburst of the nova, spreading outwards with its velocity of 186,000 m.
Fleming, Electric Wave Telegraphy (London, 1906); R.
When, however, in 1575 a new wave of plague passed over Europe, its origin was referred to Constantinople, whence it was said to have spread by sea to Malta, Sicily and Italy, and by land through the Austrian territories to Germany.
In short, if we regard the history of this disease as a whole, it appears to have lost such power from the time of the Great Plague of London in 1665, which was part of a pandemic wave, until the present day.
This list is probably by no means exhaustive, but it sufficiently indicates in a summary fashion the extent of that wave of diffusion which set in during the closing years of the 19th century.
Plague was recognized at Hong Kong in May 1894, and there can be little doubt that it was imported from Canton, where a violent outbreak-said to have caused ioo,000 deaths-was in progress a few months earlier, being part of an extensive wave of infection which is believed to have come originally out of the province of Yunnan, one of the recognized endemic centres, and to have invaded a large number of places in that part of China, including Pakhoi and other seaports.
The new synthesis reveals a universal decline from the 5th to the 10th centuries, while the Germanic races were learning the rudiments of culture, a decline that was deepened by each succeeding wave of migration, each tribal war of Franks or Saxons, and reached its climax in the disorders of the 9th and 10th centuries when the half-formed civilization of Christendom was forced to face the migration of the Northmen by sea, the raids of the Saracen upon the south and the onslaught of Hungarians and Sla y s upon the east.
If the range of the independent variable or variables is unlimited, the value of in is at our disposal, and the solution gives us the laws of wave-propagation (see WAVE).
A similar result follows in a lesser degree a wave of emigration.
Before a wave of progress has reached our shores we have had the opportunity of watching it as spectators, and of considering how we shall receive it.
While still a young man he had been affected by the wave of liberalism then spreading all over Italy, and soon after his marriage he began to conspire mildly against the Bourbon government.
Hertz then devised a wave detecting apparatus called a resonator.
Marconi applied a modified and improved form of Branly's wave detector in conjunction with a novel form of radiator for the telegraphic transmission of intelligence through space without wires, and he and others developed this new form of telegraphy with the greatest rapidity and success into a startling and most useful means of communicating through space electrically without connecting wires.
Sometimes, it must be owned, his realism is rather coarse and brutal, but when he paints the forests of Franche-Comte, the "Stag-Fight," "The Wave," or the "Haunt of the Does," he is inimitable.
Coquimbo was swept by a tidal wave in 1849, and Concepcion and Talcahuano were similarly destroyed in 1835.
The great earthquake which partially destroyed Valparaiso in 1906, however, was not followed by a tidal wave.
Consequently the monochromatic class includes the aberrations at reflecting surfaces of any coloured light, and at refracting surfaces of monochromatic or light of single wave length.
The refractive indices for different wave lengths must be known for each kind of glass made use of.
On the emission theory the velocity should be accelerated by an increase of density in the medium; on the wave theory, it should be retarded.
A wave of eclecticism passed over all the Greek schools in the 1st century B.C. Platonism and scepticism had left undoubted traces upon the doctrine of such a reformer as Panaetius.
The next great wave of Celts recorded was that which swept down on north Italy shortly before 400 B.C. These invaders broke up in a few years the Etruscan power, and even occupied Rome herself after the disaster on the Allia (390 B.C.).
He also calculated the effect of surface-tension on the propagation of waves on the surface of a liquid, and determined the minimum velocity of a wave, and the velocity of the wind when it is just sufficient to disturb the surface of still water.
These rapidly descend in Newton's scale and at last disappear, showing that the thickness of the film is less than the tenth part of the length of a wave of light.
Of these, the waves of minimum velocity form a stationary wave nearest to the front of the body.
Between the body and this first wave the surface is comparatively smooth.
Then comes the stationary wave of minimum velocity, which is the most marked of the series.
If the current-function of the water referred to the body considered as origin is Ili, then the equation of the form of the crest of a wave of velocity w, the crest of which travels along with the body, is d =w ds where ds is an element of the length of the crest.
To integrate this equation for a solid of given form is probably difficult, but it is easy to see that at some distance on either side of the body, where the liquid is sensibly at rest, the crest of the wave will approximate to an asymptote inclined to the path of the body at an angle whose sine is w/V, where w is the velocity of the wave and V is that of the body.
But those whose wave-length is near to that of the wave of minimum velocity will diverge less than any of the others, so that the most marked feature at a distance from the body will be the two long lines of ripples of minimum velocity.
As will be seen from this account, the figure-of-8 or wave theory of stationary and progressive flight has been made the subject of a rigorous experimentum crucis.
- Wave track made by the wing in progressive flight.
a, b, Crests of the wave; c, d, e, up strokes; x, x, down strokes; f, point corresponding to the anterior margin of the wing, and forming a centre for the downward rotation of the wing (a, g); g, point corresponding to the posterior margin of the wing, and forming a centre for the upward rotation of the wing (d, f).
On the south coast, opposite the broadest part of the lake, are precipitous walls of red sandstone, extending about 14 m., famous as the Pictured Rocks, so called from the effect of wave action on them.
Wave action is seen in the numerous caverns, and south-east of Portland Bill, the southern extremity of the isle, is a bank called the Shambles, between which and the land there flows a dangerous current called the Race of Portland.
In truth, however, he was lifted by the wave he seemed to command.
high, is an active volcano, and its eruptions and earthquakes have frequently brought destruction, as notably in 1852, when the damage was chiefly due to a huge wave of the sea.
A very strong "bore" or tidal wave runs up the estuary of the Meghna at spring tides, and a singular sound like thunder, known as the "Barisal guns," is often heard far out at sea about the time it is coming in.
A new intellectual wave was breaking over Western Europe, symbolized by the university and the scholastic movements; and a new spirit of democratic freedom was making itself felt in the growing commercial towns of Italy and Germany.
From the 6th to the 12th century, wave after wave of barbarian conquerors, Goths, Tatars, Sla y s and others, passed over the country, and, according to one school of historians, almost obliterated its original Daco-Roman population; the modern Vlachs, on this theory, representing a later body of immigrants from Transdanubian territory.
A wave of feeling spread amongst the different Kaffir tribes on the colonial frontier, and after the Gaika-Galeka War there followed in 1879 a rising in Basutoland under Moirosi, whose cattle-raiding had for some time!past caused considerable trouble.
If the Bond aroused disloyalty and mistaken aspirations in one section of the Cape inhabitants, it is equally certain that it caused a great wave of loyal and patriotic enthusiasm to pass through another and more enlightened section.
In open places that height is seldom more than about one and a half times the square root of the " fetch " or greatest distance in nautical miles from which the wave has travelled to the point in question; but in narrow reaches or lakes it is relatively higher.
Above this again, the height of the wave should be allowed for " wash," making the embankment in such a case not less than 54 ft.
one sense, a consequence of the revolutionary wave which had swept over Europe in 1848.
The wave of popularity which had carried Lord Palmerston to victory in 1857 had lost its strength.
In its three last sessions it was destined to sink into gradual disrepute; and it was ultimately swept away by a wave of popular reaction, as remarkable as that which had borne it into power.
If Lord Beaconsfield had dissolved parliament immediately after his return from Berlin, it is possible that the wave of popularity which had been raised by his success would have borne him forward to a fresh victory in the constituencies.
The new minister had been swept into power on a wave of popular favor, but he inherited from his predecessors difficulties Glad- in almost eyery quarter of the world; and his own stones language had perhaps tended to increase them.
Beneath these layers are masses of salter water, through which a thermal wave of small amplitude is slowly propagated to the bottom by conduction.
It was this motive which first induced the Thessalians to leave their home in Epirus and descend into this district, and from this movement arose the expulsion of the Boeotians from Arne, and their settlement in the country subsequently called Boeotia; while another wave of the same tide drove the Dorians also southward, whose migrations changed the face of the Peloponnese.
In other places they wave green branches, and on the south coast, pour water over their heads, a custom noticed by Cook at Mallicolo (New Hebrides).
The amount of retardation does not admit of accurate computation, owing to the uncertainty both as to the amount of the oceanic friction from which it arises and of the exact height and form of the tidal wave, the action of the moon on which produces the effect.
The literary efforts of young Ireland eventuated in another rebellion (1848); a revolutionary wave could not roll over Europe without touching the unlucky island.
The Greek " key " pattern found on objects in Peruvian graves was not necessarily borrowed from Greece, nor did Greeks necessarily borrow from Aztecs the " wave " pattern which is common to both.
a crystalline plate of such a thickness that it introduces a relative retardation of a quarter of a wave between the component streams within it.
Let a, 0, be the angles that the primitive and final planes of polarization and the plane of polarization of the quicker wave within the plate make with a fixed plane, and let be the relative retardation of phase of the two streams on emergence from the plate for light of period T.
Airy extended Fresnel's hypothesis to directions inclined to the axis of uniaxal crystals by assuming that in any such direction the two waves, that can be propagated without alteration of their state of polarization, are oppositely elliptically polarized with their planes of maximum polarization parallel and perpendicular to the principal plane of the wave, these becoming practically plane polarized at a small inclination to the optic axis.
- Huygens satisfactorily explained the laws of reflection and refraction on the principles of the wave theory, so far as the direction of the waves is concerned, but his explanation gives no account of the intensity and the polarization of the reflected light.
But this wave of the ebbing Moslem tide had less force than the Almorvide, and fell back both sooner and farther than its predecessor.
A wave of Clericalism and ultra-Catholic influences swept over the land, affecting the middle classes, the universities and learned societies, and making itself very perceptible also among the governing classes and both dynastic parties, Liberals and Conservatives.
from about 4000 B.C. 1 a wave of Semitic migration poured out of Arabia, and flooded Babylonia certainly, and possibly, more or less, Syria and Palestine also.
Also that between 2800 and 2600 B.C. a second wave from Arabia took the same course, covering not only Babylonia, but also Syria and Palestine and probably also Egypt (the Hyksos).
Earthquakes of great violence were recorded in 1847 and 1881 (with tidal wave), and mild shocks were experienced in December 1899.
Much of his time was given to writing and revising the lectures on the wave theory of light which he had delivered at Johns Hopkins University, Baltimore, in 1884, but which were not finally published till 1904.
In optics, he developed the wave theory, and his name is associated with the simple dispersion formula.
It was at the close of the Wealden period that a second evolutionary wave swept over the vegetation of the world.
Several methods have been employed for making observations of the form of alternating current curves - (1) the point-by-point method, ascribed generally to Jules Joubert; (2) the stroboscopic methods, of which the wave transmitter of H.
If the contact springs can be moved round the disk so as to vary the instant of contact, we can plot out the value of the observed instantaneous voltage of the machine or circuit in a wavy curve, showing the wave form of the electromotive force of the alternator.
The voltmeter needle may then be made to record its variations graphically on a drum covered with paper and so to delineate the wave form of the current.
As the brushes are slowly shifted over on the revolving contact so as to select different phases of the alternating electromotive force, the pen follows and draws a curve delineating the wave form of that electromotive force or current.