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hypotheses of either system, we are persuaded, a all, attended to. And it appears to be a sufi theory of dreaming, if not perfectly satisfactory, cient confirmation of this theory, that persons in at least less exceptionable than any of the above, good health, and engaged in active employments, may be drawn from merely attending to a simple most commonly dream of those matters wherein tact that frequently takes place when we are they are daily occupied; the uniform current of awake. Erery person must have observed, that their ideas when awake, seldom taking any other when alone, and while his attention is not called direction during sleep; whereas, persons in a to any particular subject, either by study, con- had habit of body, or weak state of mind, and versation, manual labor, sudden noise, or the those who take little exercise, or who are not objects around him, a kind of involuntary ino- engaged in active business, have generally wild tion, so to speak, will take place in his ideas; and extravagant dreams, and sometimes very and that, if he makes no voluntary exertion of disagreeable ones, of monsters, mad dogs, devils, mind to fix his attention upon one idea more deep pits, houses on fire, stormy oceans, and the than another, a rapid succession of very different like. In a word, when we consider the operaideas, some old and some recent, will occur in tions of our minds when awake, particularly of the course of a few minutes. Every person, that active faculty, the imagination, how readily who attends church regularly, or who has at upon hearing, reading, or speaking of any person, tended the lectures of an unentertaining public place, action, or circumstance, it forms an idea speaker, must be sensible, that such involuntary in the mind of such person, place, &c., though, Inotions of his ideas have often taken place, perhaps, many years have elapsed since we saw wben, either through the fault of the speaker, or them, or even though we have never seen them, that of the hearer, his attention has not been we need not be surprised, that the same active sufficiently fixed upon what was spoken. A faculty should be able, when uncontrolled by the person much addicted to study, and to the habit will and judgment, and but partially assisted by of fixing his ideas constantly upon one subject the memory, to raise up a series of images in or another, may, perhaps, be less sensible of the succession, and thus to create an ideal world, and involuntary motion we here allude to, than various ideal transactions in the mind. others; but let such a studious person be placed The late Mr. Rennell, of Kensington, consiin a company where a trifling conversation is ders dreams to afford satisfactory proof that the going on, and he will soon find himself in the mind can act without the intervention of the situation here described. A current of ideas will brain: upon this it has been well remarked, that rapidly intrude upon his mind, and carry off we have not as yet sufficient data from which to his attention from the trifles in which those around estimate the degree of dependence of the former him are engaged; and thus subject him to what upon the latter, still we have no facts founded is commonly called absence of mind. And it upon our present state of being, which can estawill also be admitted that the most studious, as blish the total independence which he supposes. well as the most thoughtless, will sometimes find The proximate cause of sleep is undoubtedly an idea of a long forgotten fact, sentiment, or corporeal, and, perhaps, consists in a certain circumstance, suddenly recurring to their minds, inaptitude of the brain to receive the usual imwithout any seeming cause. The inference we pulses of its immaterial tenant. When this inwould draw from all these facts, to our present aptitude amounts to complete quiescence, the subject, is, that during sleep, a similar involun- soul cannot display itself, because the instrument tary motion, or current of ideas, takes place; of its operations is in a state of repose. In such but that, in consequence of the fatigue occasioned circumstances the sleep is profound, and no by the labors of the day (no matter whether these dreams take place. This repose or quiescence operate by exhausting the excitability, or by oc- of the brain may be increased to absolute torpor casioning a deficiency of the nervous fluid), the for a season, as is seen in the hyhernation of anithree chief powers of the mind—the will, the mals, and in those rare cases in the human spejudgment, and the memory, are rendered in a cies, where persons have remained for several considerable degree inactive; at least, in so far, hours, or even days, in a trance. When this that the will has no power over these faculties, torpor of the cerebral system abates, the immawhile the imagination, rendered more active, as terial principal is again enabled to resume its it would seem, by being freed from the control operations, owing to the renewed capabilities of of both the will and the judgment, gives every the instrument. Thus, as the cause of sleep is new idea that occurs a visionary form; and thus corporeal, there are strong grounds for presupucreates a fresh and rapid succession of various ing that the cause of dreams is corporeal also. images, according to the unlimited current of They occur oftenest when there is
irritation uncontrolled ideas that succeed each other. How of the system in general, or of the brain in parthis happens, perhaps, the human faculties will ticular, hindering the complete repose of that never be able to comprehend or explain; at least, part. When this irritation is great, as in general till they shall be capable of explaining the con- fever, accompanied with increased action of the nexion by which the soul and body are united, blood-vessels within the head, sleep is often enif, indeed, mankind shall ever attain to such à tirely prevented; or if it does take place, it is degree of perfection in physiology. But that disturbed with frightful illusions. What is the dreams take their rise chiefly, if not solely, from precise state of the soul at such times, is a disthe mere succession of ideas, dressed into form puted point amongst metaphysicians. Perhaps, by the imagination, uncontrolled by the will or on so dark a subject, it may be allowable to hathe judgment, appears to us to be undoubted zard a conje are, that the operations of the fact, though hitherto it would seem little, if at immaterial being are modified by the semi
quiescence of the material organ, and that this
But the good knight want of correspondence between the agent and Full of sad feare and ghastly dreriment, the instrument is the cause of the wild imagina
When all this speech the living tree had spent, tions and false judgments that distinguish our
The bleeding bough did thrust into the ground. dreams from our waking thoughts. Dreains,
Spenser. Facrie Qucene. therefore, instead of proving the contrary, rather
In urns and altars round, tend to show that the dependence of the imma- A drear and dying sound terial upon the material part is perpetual and Affrights the flamens at their service quaint. Milton. without exception, during the continuance of Obscure they went through dreary shades, that led man's existence upon earth.
Along the vast dominions of the dead. Dryden, In whatever way we attempt to account for Towns, forests, herds, and men promiscuous the manner, in which our powers of mind and
drowned, body perform their functions in dreaming, we With one great death deform the dreary ground.
Prior. can, at least, apply to useful purposes the imperfect knowledge which we have been able to
So with his dread Caduceus Hermes led acquire concerning this series nf phenomena.
From the dark regions of the imprisoned dead, Our dreams are affected by the state of our
Or drove in silent shoals the lingering train
To night's dull shore, and Pluto's dreary reigo. health, by the manner in which we have passed
Darwin. the preceding day, by our general habits of life, by the hopes which we most fondly indulge, and
It struck even the besiegers' ear the fears which prevail most over our fortitude
With something ominous an'i drear,
An undefined and sudden thrill, when awake. From recollecting our dreams,
Which makes the heart a moment still. therefore, we may learn to correct many impro
Byron. prieties in our conduct; to refrain from bodily
O luxury! exercises, or from meats and drinks that have Bane of elated life, of affluent state , unfavorable effects on our constitution ; to resist, What dreary change, what ruin, is not thine? Id. in due time, evil habits that are stealing upon
DREDGE, v. a. & n. s. Sax. drægan, to us; and to guard against hopes and fears which
DREDGʻER, n. S.
• } detach us from our proper concerns, and unfit us for the duties of life . Instead of thinking ther into a particular kind of met: the net used :
(or of dregs?) this word is a corruption. To gawhat our dreams may forebode, we may, with much better reason, reflect by what they have a dredger is one who uses such a net; and, perbeen occasioned, and look back to those circum- four on meat, or amongst pastry; called also a
haps from its net-like top, a box for scattering stances in our past life, to which they are owing: The sleep of innocence and health is sound and
dredging-box. refreshing; their dreams delightful and pleasing.
For oysters they have a peculiar dredge; a thick, A distempered body, and a polluted or perturbed strong net
, fastened to three spills of iron, and draw mind, are haunted in sleep with frightful, im
at the boat's stern, gathering whatsoever it meetech lying in the bottom.
Careve. pure, and unpleasing dreams. The reader who is disposed to speculate farther on this subject,
The oysters dredged in the Lyne find a welcome may consult Dr. Beattie's Essays, Hartley on
acceptance. Man, and the principal writers on physiology.
DREDGING, in civil engineering, is the art We may add, some very beautiful fables have of removing mud, silt, or other depositions from been written both by ancients and moderns in the bed of rivers, canals, harbours, or docks; the form of dreams. The Somnium Scipionis is and is accomplished by various tools and deone of the finest of Cicero's compositions. In scriptions of machinery. the periodical publications, which have diffused
The common dredging-boat or barge is worked so much elegant and useful knowledge through by two or more men, by whom the gravel, or Great Britain, the Tatlers, Spectators, Guardians, ballast, is taken up in a leather bag, the month &c., we find a number of excellent dreams. of which is extended by an iron hoop, attached Addison excelled in this way of writing. The to a pole, of sufficient length to reach the bot. public are now less partial to this species of tom: in the small way, two men are employed coroposition than formerly. Dr. Beattie, in his to work each pole. The barge being moored, one valuable Essay on Dreaming, quotes a very fine of the men takes his station at the steru, with the one from the Tatler, and gives it due praise.
pole and bag in his hand, the other stands in the DREAR, adj. & n. s. Sax. dreorig; Belg.
head, having hold of a rope, tied fast to the boop DREARʻY, adj. treuer; from Goth.verb
of the leather bag. The man at the stern now DREAR'IHEAD, n. s.
rygga, to lament. All puts the pole and bag down, over the barge's DREAR'IMENT,
the substantives signify side, to the bottom, in an inclined position. The DRLAR'INESS.
sorrow, united with hoop being farthest from the man in the head of fear: drear and dreary are, dismal; mournful ; is fast to the gunwale of the barge, he passes it
the barge, and having a rope, one end of which fearful. The ill-faced owl, death's dreadful messenger;
twice or thrice round the pole, and then holds The hoarse night raven, trump of doleful drear.
it tight: the man in the head now pulls the rope, Spenser.
fastened to the hoop, and draws the hoop and bag The messenger of death, the ghastly owl,
along the ground, the other allowing the pole With dreary shrieks did also yell;
to slip through the rope as it approaches the And hungry wolves continually did howl
vertical position, at the same time causing such a Al her abhorred face, so horrid and so foul. friction, that the hoop digs into the ground, the
Id. Faerie Queene. leather bag receiving whatever passes through the
hoop: both men now assist in getting a bay into means of a cast iron wheel at G in the plan, the barge, and delivering its contents. When the wedged on the end of the axis of the upper bag is large, several men are employed; and, to trundle (). The wheel is cast hollow, like a very increase the effect, a windlass, with wheel-work, short cylinder, and has several screws tapped is sometimes used. A chain or rope is brought through its rim, pointing to the centre, and presto the winch from the spoon, through a block sing upon the circumference of another wheel suspended from a small crane for bearing the enclosed within the hollow of the first, that it spoon and its contents to the side of the boat, may slip, round in the other, where any power and bringing it over the gunwale to be emptied greater than the friction of the screw is applied ; into it. The purchase rope is led upon deck by the internal wheel is wedged on the same shaft a snatch block in the proper direction for the with a large cog-wheel f, turned by the small barrel of the winch. From two to four men, cog-wheel g, on the axis of the steam-engine. can with this simple apparatus, lift from twenty The steam-engine is one of that kind called to sixty tons in a tide, from a depth of from two high pressure, working by the expansive force and a half to three fathoms, when the ground is fa- of the steam only, without condensation; h is vorable. In this manner the convicts at Woolwich the boiler containing the fire-place and cyupon the Thames, have been long employed to linder within it; i is one of the connecting rods, perform the ballast-heaving, or dredging. and I the fly wheel on the other end of the same
The bucket dredging-machine, whether worked shaft as the wheel g. The pulleys a, which susby men, hoặses, or the steam-engine, is a great pend the chain frame, are reeved with an iron improvement on the above. The frame-work chain, the tackle fall of which passes down consists of two beams of timber, supported on a through the ship's deck, and is coiled on a roller rod of iron with shores of wood; on these them in the plan, and represented by a circle in the full buckets move upon iron rollers fixed to elevation : on the end of the roller is a cog-wheel the timber, while the empty buckets, attached to p, turned by the engine wheel g: the bearing of and guided by an endless chain, form a curve in this wheel is fixed upon a lever, one end of which descending to the bottom; as they respectively comes near that part of the steam-engine, where arrive they are intended to excavate or scoop up the cock, which regulates the velocity of the the silt or gravel from the ground. The opera- engine, is placed ; so that one man can command tion of lowering and raising the frame once both lever and cock, and, by depressing that end performed by crane-work, distinct from the of the lever, cause the wheel p to geer with g, machinery of the steam-engine, is now also accom- and consequently be turned thereby, and wind plished by a power taken from it.
up the chain of the pulleys ;g is a strong curved Plate DREDGING MachinES, AA, fig. 1, is iron bar bolted to the vessel's side and gunwale, a frame of timber bolted to the starboard gun- passing through an eye bolted to the frame E, to wale, to support a large horizontal beam BB, keep the frame to the vessel's side, that the tide fig. 2; another similar frame is fixed up in the or other accident may not carry it away. middle of the ship at D, fig. 2, and the end of A hopper or trough is suspended beneath the the beam is sustained by an upright post bolted wheel o, by ropes from the beam B, into which to the opposite gunwale; the starboard end of the buckets b, b, b, empty the ballast they bring the beam projects over the vessel's side, and has from the bottom; the hopper conveys it into a an iron bracket S fastened to it, to support one barge brought beneath it; this hopper is not of the bearings for the long frame E E, composed shown in the plate, as it would tend to confuse of four timbers bolted together : the other end parts already not very distinct. The motion of the of the frame is suspended by pulleys a, a ; from whole machine is regulated by one man. The vessel a beam F fixed across the stern, the upper ends being moored fast, the engine is started, and turns of the outside beams of the frame EE have the chain of buckets : the engine tender now puts each a stout iron bolted to them, which are per- his foot upon a lever, disengages the wheel p forated with two large holes to receive two short from g, and by another takes off a gripe which cast iron tubes, one fastened to the iron bracket embraced the roller m. This allows the end E S at the end of the beam B, and the other to a of the frame to descend, until the buckets on the cross beam of the frame A; these tubes act as lower half of the chain drag on the ground, as the pivots of the frame E, upon which it can be shown in fig. 1, when he stops the further descent raised or lowered by the pulleys a, a: they also by the gripe, the buckets are filled in succession contain bearings for an iron axis, on which a at the lower end of the frame, and brought up wheel or trundle () is fixed, containing four to the top, where they deliver their contents into rounds. Another similar trundle P is placed at the hopper before-mentioned : as they take away the bottom of the frame EE, and two endless the ballast from the bottom, the engine tender chains k,k, pass round both, as is seen in the lets the frame E down lower by means of the plan. Between every other link of the two gripe lever, and keeps it at such a height that the chains, a bucket of plate iron bbb is fastened, buckets come up nearly full; if at any time the and, as the chain runs round, the buckets bring buckets get such deep hold as to endanger the up the soil ; a number of cast iron rollers d, d, breaking of the chain or stopping the engine, are placed between the beams of the frame to the coupling-box at G before-described, suffers support the chain and buckets as they roll up the steam-engine to turn without moving the Four rollers e,e, are also placed on each of the chain of buckets, and the engine tender, pressing outside beams, to keep the chains in their places his foot upon the lever which brings the wheel p on the frame, that they may not get off to one to geer with g, causes the roller n to be turned side. The motion is conveyed to the chains by by the engine, and raise up the frame E, until