Historick marbles to record his praise. Id. From opening skies may streaming glories shine, And saints embrace thee. Id. STREATER (Robert), an English painter, born in 1624. He was esteemed the most universal painter England ever bred. At the restoration in 1660 he was made serjeant painter to the king. He died of the stone in 1680. in the lordship of Stargard in the midst of lakes and marshes. It is divided into Old and New Strelitz, which form properly two towns, a mile distant from each other. Old Strelitz was formerly the ducal residence, but the palace having been burned in 1713, the duke built a new one at Glienke, a place at a little distance, and in 1733 founded a town called New Strelitz. The two came in time to be considered as one town. Old Strelitz contains 3000 inhabitants. New, a better built place, has 4000, with a distinct magistracy. The manufactures consist of woollen, linen, and, in a small degree, of tobacco. Here are also the public offices of the duchy. Fiftyseven miles north by west of Berlin. STRENA (Lat.), in Roman antiquity, new year's gifts, or presents made on the first day of the year, as a happy omen, and mark of the giver's good will. This practice took place so early as the reign of Titus Tatius, king of the Sabines, and colleague of Romulus; who having received on the first day of the year a present of some sprigs of vervain, gathered in a wood consecrated to the goddess Strenia, authorised this custom to be observed afterwards, and gave to all such presents the name of Strenæ. The Romans on that day celebrated a festival in honor of Janus and Juno. See YEAR. STRENGTH, n. s. & v. a.STRENGTHEN, v. a. & v. n. STRENGTHENER, n. s. STRENG THLESS, adj. STRENGTHNER, n. S. Sax. strengð; Teut. and Belg. streng; Gothic See dreing. power; force; firmness; power of resistance; security hence mental power; animation; validity; argumentative force or prevalence; a fortification or fortress: used by Daniel for to strengthen, which signifies to make strong; increase in power or strength; confirm; establish; animate: and, as a verb neuter, to grow STREET, n. s. Sax. rtnær; Isl. strada; strong a strengthener is that which gives A strength: strengthless, weak; wanting or deDan. streede; Belg. straet; Lat. stratum. way; properly a paved way between rows of prived of strength. houses; a public place or way. That there be no leading into captivity, and no Ps. cxliv. 14. complaining in our streets. Sandys. The streets are no larger than alleys. He led us through fair streets; and all the way we went there were gathered people on both sides, standing in a row. When night Bacon. Darkens the streets, then wander forth the sons Milton. The Italians say the ancients always considered the situation of a building, whether it were high or low, in an open square, or in a narrow street, and more or less deviated from their rule of art. should want street-room. Addison on Italy. Our publick ways would be so crowded, that we Id. Spectator. Let us reflect upon what we daily see practised in the world; and can we believe, if an apostle of Christ appeared in our streets, he would retract his caution, and command us to be conformed to the Rogers's Sermons. When you tattle with some crony servant in the same street, leave your own street-door open. Swift. world? STRELITZ, a city of Germany, capital of the grand duchy of Mecklenburg-Strelitz, is situated Charge Joshua, and encourage him, and strengthen Deuteronomy. him. Let us rise up and build: so they strengthened their hands for this work. Nehemiah ii. 18. They sought the strengthening of the heathen. 1 Maccabees vi. This presupposed, it may then stand very weli with strength and soundness of reason thus to answer. Hooker. Our castle's strength Shakspeare. Id. Antony and Cleopatra. Id. Henry VI. As the wretch, whose fever-weakened joints, Id. Henry IV. The rashness of talking should not only be retarded by the guard of our heart, but fenced in by certain strengths placed in the mouth. Ben Jonson's Discoveries. Edward's happy-ordered reign most fertile breeds Plenty of mighty spirits, to strength his state. Daniel. Strength there must be either of love or war, even such contrary ways leading to the same unity. Holyday. Betrayed in all his strengths, the wood beset; All instruments, all arts of ruin met. Denham. Thou must outlive appearance of ingenuity. There is nothing in which this want of scientific education, this ignorance of principle, is so frequently observed, as in the injudicious proportion of the parts of machines and other mechanical structures; pro Thy youth, thy strength, thy beauty, which will portions and forms of parts in which the strength change To withered, weak, and grey. He thought Milton. Id. This inaccessible high strength to have seized. Oh men for flattery and deceit renowned! Thus when y' are young ye learn it all like him; Till, as your years increase, that strengthens too, T'undo poor maids. Otway's Orphan. Authority is by nothing so much strengthened and confirmed as by custom; for no man easily distrusts the things which he and all men have been bred up to. Temple. Garlick is a great strengthener of the stomach, upon decays of appetite, or indigestion. This liquor must be inflammable or not, and yet subtile and pungent, which may be called spirit; or else strengthless or insipid, which may be named phlegm. Id. Boule. Aristotle's large views, acuteness, and penetration of thought, and strength of judgment, few have equalled. Locke. What they boded would be a mischief to us, you are providing shall be one of our principal strengths. Sprat's Sermons. The allies, after a successful summer, are too apt, upon the strength of it, to neglect their preparations for the ensuing campaign. Addison. He enjoyed the greatest strength of good sense, and the most exquisite taste of politeness. Id. We, like friendly colours, found our hearts unite, And each from each contract new strength and light. Pope. The disease, that shall destroy at length, Grows with his growth, and strengthens with his strength. Id. If it were true that women were thus naturally vain and light, then how much more blameable is that education which seems contrived to strengthen and increase this folly! Law. STRENGTH, in mythology, the daughter of Pallas the giant, by the nymph Styx, and the sister of Valor and Victory. STRENGTH OF MATERIALS, in mechanics, is a subject of so much importance that in a nation so eminent as this for invention and ingenuity in all species of manufactures, and in particular so distinguished for its improvements in machinery of every kind, it is somewhat singular that no writer has treated it in the detail which its importance and difficulty demand. The man of science who visits our great manufactures is delighted with the ingenuity which he observes in every part, the innumerable inventions which come even from individual artisans, and the determined purpose of improvement and refinement which he sees in every workshop. Every cotton-mill appears an academy of mechanical science; and mechanical invention is spreading from these fountains over the whole kingdom. But the philosopher is mortified to see this ardent spirit so cramped by ignorance of principle, and many of these original and brilliant thoughts obscured and clogged with needless and even hurtful additions, and a complication of machinery which checks improvement even by its and position are no wise regulated by the strains to which they are exposed, and where repeated failures have been the only lessons. ment. The strength of materials arises immediately or ultimately from the cohesion of the parts of bodies. Our examination of this property of tangible matter has as yet been very partial and imperfect, and by no means enables us to apply mathematical calculations with precision and success. The various modifications of cohesion, in its different appearances of perfect softhave a mighty influence on the strength of ness, plasticity, ductility, elasticity, hardness, bodies, but are hardly susceptible of measureTheir texture also, whether uniform like glass and ductile metals, crystallised or granu. lated like other metals and freestone, or fibrous like timber, is a circumstance no less important; yet even here, although we derive some advantage from remarking to which of these forms of aggregation a subject belongs, the aid is but small. All we can do in this want of general of bodies. Accordingly, philosophers have enprinciples is to make experiments on every class deavoured to instruct the public in this particular. The Royal Society of London at its very first institution made many experiments at their meetings, as may be seen in the first registers of the Society. Several individuals have added their experiments. The most numerous collection in detail is by Muschenbroek, professor of natural philosophy at Leyden. Part of it was published by himself in his Essais de Physique, in 2 vols. 4to.; but the full collection is to be found after his death by Lulofs, in 3 vols. 4to. This in his system of Natural Philosophy, published was translated from the Low Dutch into French, by Sigaud de la Fond, and published at Paris in 1760, and is a prodigious collection of physical knowledge of all kinds, and may almost suffice for a library of natural philosophy. But this collection of experiments on the cohesion of bodies is not of that value which one expects. We presume that they were carefully made and faithfully narrated; but they were made on such small specimens that the unavoidable natural inequalities of growth or texture produced irregularities in the results, which bore too great a proportion to the whole quantities observed. We may make the same remark on the experiments of Couplet, Pitot, De la Hire, Du Hamel, and others of the French academy. In short, if we except the experiments of Buffon on the strength of timber, made at the public expense on a large scale, there is nothing to be met with from which we can obtain absolute measures which may be employed with confidence; and there is nothing in the English language, except a simple list by Emerson, which is merely a set of affirmations without any narration of circumstances, to enable us to judge of the validity of his conclusions; but the character of Mr. Emerson, as a Σ STRENGTH OF MATERIALS. man of knowledge and of integrity, gives even to these assertions a considerable value. But to make use of any experiments there must be employed some general principle by which we can generalise their results. They will other wise be only narrations of detached facts. We must have some notion of that intermedium, by the intervention of which an external force applied to one part of a lever, joist, or pillar, occasions a strain on a distant part. This can be nothing but the cohesion between the parts. It is this connecting force, which is brought into action, or, as we more shortly express it, excited. This action is modified in every part by the laws of mechanics. It is this action which is what we call the strength of that part, and its effect is the strain on the adjoining parts; and thus it is the same force, differently viewed, that constitutes both the strain and the strength. When we consider it in the light of a resistance to fracture, we call it strength: we call every thing a force, which we observe to be ever accompanied by a change of motion; or, more strictly speaking, we infer the presence and agency of a force wherever we observe the state of things in respect of motion different from what we know to be the result of the action of all the forces which we know to act on the body. Thus, when we observe a rope to prevent a body from falling, we infer a moving force inherent in the rope with as much confidence as when we observe it drag the body along the ground. The immediate action of this force is undoubtedly exerted between the immediately adjoining parts of the rope. The immediate effect is the keeping the particles of the rope together. They ought to separate by any external force drawing the ends of the rope contrarywise; and we ascribe their not doing so to a mechanical force really opposing this external force. When desired to give it a name, we name it from what we conceive to be its effect, and therefore its characteristic, and we call it cohesion. This is merely a name for the fact; but it is the same thing in all our denominations. We know nothing of the causes but in the effects; and our name for the cause is in fact the name of the effect, which is cohesion. We mean nothing else by gravitation or magnetism. What do we mean when we say that Newton understood thoroughly the nature of gravitation, of the force of gravitation; or that Franklin understood the nature of the electric force? Nothing but this: Newton considered with patient sagacity the general facts of gravitation, and has described and classed them with the utmost precision. In like manner we shall understand the nature of cohesion, when we have discovered with equal generality the laws of cohesion, or general facts which are observed in the appearances, and when we have described and classed them with equal accuracy. Let us therefore attend to the more simple and obvious phenomena of cohesion, and mark with care every circumstance of resemblance by which they may be classed. Let us receive these as the laws of cohesion characteristic of its supposed cause, the force of cohesion. We cannot pretend to enter on this vast research. The modifications are innumerable; 287 and it would require the penetration of more than Newton to detect the circumstance of similarity amidst millions of discriminating circumstances. Yet this is the only way of discovering which are the primary facts characteristic of the force, and which the modifications. The study is immense, but is by no means desperate; and we entertain great hopes that it will ere long be successfully prosecuted; but, in our particular predicament, we must content ourselves with selecting such general laws as seem to give us the most immediate information of the circumstances that must be attended to by the mechanician in his constructions, that he may unite strength with simplicity, economy, and energy. 1st, Then, it is a matter of fact that all bodies are in a certain degree perfectly elastic; that is, when their form of bulk is changed by certain moderate compressions or distractions, it requires the continuance of the changing force to continue the body in this new state; and when the force is removed the body recovers its original form. We limit the assertion to certain moderate changes: for instance, take a lead wire one-fifteenth of an inch in diameter and ten feet long; fix one end firmly to the ceiling, and let the wire hang perpendicular; affix to the lower end an index like the hand of a watch; on some stand immediately below let there be a circle divided into degrees, with its centre corresponding to the lower point of the wire; now turn this index twice round; and thus twist the wire. When the index is let go, it will turn backward again by the wire's untwisting itself, and make almost four revolutions before it stops; after which it twists and untwists many times, the index going backwards and forwards round the circle, diminishing however its arch of twist each time, till at last it settles precisely in its original position. This may be repeated for ever. Now, in this motion, every part of the wire partakes equally of the twist. The particles are stretched, require force to keep them in their state of extension, and recover completely their original relative positions. These are all the characters of what the mechanician calls perfect elasticity. See ELASTICITY. This is a quantity quite familiar in many cases; as in glass, tempered steel, &c., but was thought incompetent to lead, which is generally considered as having little or no elasticity. But we make the assertion in the most general terms, with the limitation to moderate derangement of form. We have made the same experiment on a thread of pipe-clay, made by forcing soft clay through the small hole of a syringe by means of a screw; and we found it more elastic than the lead wire: for a thread of one-twentieth of an inch diameter and seven feet long allowed the index to make two turns, and yet completely recovered its first position. 2dly. But, if we turn the index of the lead wire four times round, and let it go again, it untwists again in the same manner, but it makes little more than four turns back again; and after many oscillations it finally stops in a position almost two revolutions removed from its original position. It has now acquired a new arrangement of parts, and this new arrangement is permanent like the former; and, what is of particular moment, it is perfectly elastic. This change is familiarly known by the denomination of a set. The wire is said to have taken a set. When we attend minutely to the procedure of nature in this phenomenon, we find that the particles have as it were slid on each other, still cohering, and have taken a new position, in which their connecting forces are in equilibrio; and in this change of relative situation it appears the connecting forces, which maintained the particles in their first situations, were not in equilibrio in some position intermediate between that of the first and that of the last form. The force required for changing this first form augmented with the change, but only to a certain degree; and during this process the connecting forces always tended to the recovery of this first form. But, after the change of mutual position has passed a certain magnitude, the union has been partly destroyed, and the particles have been brought into new situations; that the forces which now connect each with its neighbour tend, not to the recovery of the first arrangement, but to push them farther from it, into a new situation, to which they now verge, and require force to prevent them from acquiring. The wire is now in fact again perfectly elastic; that is, the forces which now connect the particles with their new neighbours augment to a certain degree as the derangement from this new position augments. This is reasoning not from any theory. It is narrating facts on which a theory is to be founded. What we have been just now saying is evidently a description of that sensible form of tangible matter which we call ductility. It has every gradation of variety, from the softness of butter to the firmness of gold. All these bodies have some elasticity; but we say they are not perfectly elastic, because they do not completely recover their original form when it has been greatly deranged. The whole gradation may be most distinctly observed in a piece of glass or hard sealing-wax. In the ordinary form glass is perhaps the most completely elastic body that we know, and may be bent till just ready to snap, and yet completely recovers its first form, and takes no set whatever; but when heated to such a degree as just to be visible in the dark, it loses its brittleness, and becomes so tough that it cannot be broken by any blow; but it is no longer elastic, takes any set and keeps it. When more heated it becomes as plastic as clay; but in this state is remarkably distinguished from clay by a quality which we may call viscidity, which is something like elasticity, of which clay and other bodies purely plastic exhibit no appearance. This is the joint operation of strong adhesion and softness. When a rod of perfectly soft glass is suddenly stretched a little, it does not at once take the shape which it acquires after a short time. It is owing to this that, in taking the impression of a seal, if we take off the seal while the wax is yet very hot, the sharpness of the impression is destroyed immediately. Each part drawing its neighbour, and each part yielding, the prominent parts are pulled down and blunted, and the sharp hollows are pulled upwards and also blunted. The seal must be kept on till all has become not only stiff but hard. This viscidity is to be observed in all plastic bodies which are homogeneous. It is not observed in clay, because it is not homogeneous, but consists of hard particles of the argillaceous earth sticking together by their attraction for water. Something like it might be made of finely powdered glass and a clammy fluid such as turpentine. Viscidity has all degrees of softness till it degenerates to ropy fluidity like that of olive oil. When ductility and elasticity are combined, in different proportions, an immense variety of sensible modes of aggregation may be produced. Some degree of both is probably to be observed in all bodies of complex constitution; that is, which consist of par ticles made up of many different kinds of atoms. Such a constitution of a body must afford many situations permanent, but easily deranged. In all these changes of disposition which take place among the particles of a ductile body, the particles are at such distance that they still cohere. The body may be stretched a little; and, on removing the extending force, the body shrinks into its first form. It also resists moderate compressions; and when the compressing force is removed the body swells out again. Now the corpuscular fact here is, that the particles are acted on by attractions and repulsions, which balance each other when no external force is acting on the body, and which augment as the particles are made, by any exter nal cause, to recede from this situation of mutual inactivity; for since force is requisite to produce either the dilatation or the compression, and to maintain it, we are obliged, by the constitution of our minds, to infer that it is opposed by a force accompanying or inherent in every particle of dilatable or compressible matter: and as this necessity of employing force to produce a change indicates the agency of these corpuscular forces, and marks their kind according as the tendencies of the particles appear to be toward each other in dilatation, or from each other in compression; so it also measures the degrees of their intensity, Should it require three times the force to produce a double compression, we must reckon the motual repulsions triple when the compression is doubled; and so in other instances. We see from all this that the phenomena of cohesion indicate some relation between the intensity of the force of cohesion and the distance between the centres of the particles. To discover this relation is the great problem in corpuscular mechanism, as it was in the Newtonian investigation of the force of gravitation. Could we discover this law of action between the corpuscles with the same certainty and distinctness, we might with equal confidence say what will be the result of any po sition which we give to the particles of bodies: but this is beyond our hopes. The law of gravi tation is so simple that the discovery or detection of it amid the variety of celestial phenomena required but one step; and in its own nature its possible combinations still do not greatly exceed the powers of human research. One is almost disposed to say that the Supreme Being has exhibited it to our reasoning powers as sufficient to employ with success our utmost efforts, but not so abstruse as to discourage us from the noble attempt. It seems to be otherwise with respect to cohesion. Mathematics informs us that, if it deviates sensibly from the law of gravitation, the simplest combinations will make the joint action Though the faculties of the mind are improved by exercise, yet they must not be put to a stress beyond their strength. Id. Consider how great a stress he laid upon this duty, while upon earth, and how earnestly he recomAtterbury. Sax. repecan; mended it. STRETCH, v. a., v. n., & Į STRETCH'ER, n. s. [n. s. 1 Belgic strecken. To extend; spread out to a distance; elongate; expand; strain: to be extended; bear extension; push beyond the truth: as a noun substantive reach; extension; effort: struggle; utmost reach: a stretcher is any instrument of extension. Take thy rod, and stretch out thine hand. of several particles an almost impenetrable mystery. We must therefore content ourselves, for a long while to come, with a careful observation of the simplest cases that we can propose, and with the discovery of secondary laws of action, in which many particles combine their influence. Our readers are requested to accept of these endeavours, not so much to communicate information on this important and difficult subject, as to excite curiosity and farther experiments. Many useful deductions might be made from these premises respecting the manner of disposing and combining the strength of materials in our structures. The best form of joints, mortises, tenons, scarfs; the rules for juggling, tabling, faying, fishing, &c., practised in the delicate art of mastmaking, are all founded on this doctrine: but the discussion of these would be equivalent to writing a complete treatise of carpentry. We hope that this will be executed by some intelligent mechanician; for there is nothing in our language on this subject but what is almost contemptible; yet there is no mechanic art that is more suscep What! will the line stretch out to the' crack of tible of scientific treatment. Such a treatise, if well executed, could not fail of being well received by the public in this age of mechanical improve ment. STRENGTHENERS, or corroborants, sucn medicines as add to the bulk and firmness of the solids; and such are all agglutinant and astringent medicines. See MATERIA MEDICA. STRENUOUS, adj Lat. strenuus. Brave; Milton's Agonistes. Many can use both hands, yet will there divers remain that can strenuously make use of neither. Browne's Vulgar Errours. There was no true catholick but strenuously contended for it. Waterland. He resolves to be strenuous for taking off the test, against the maxims of all wise Christian governments, which always had some established religion, leaving at best a toleration to others. Swift to Pope. Writers dispute strenuously for the liberty of conscience, and inveigh largely against all ecclesiasticks under the name of high church. Swift. STREP'EROUS, adj. Lat. strepo. Loud; Spenser. By stress of weather driven, better. Exodus vii. 19. The stretching out of his wings snall fill the breadth of thy land. Isaiah viii. 8. Idolatry is a horrible sin, yet stretch unto it. doth repentance Whitgifte. This kiss, if it durst speak, doom? Shakspeare. King Lear. Shakspeare. His hopes enstiled Chapman. Cowley. This to rich Ophir's rising morn is known, Eden stretched her line All thy dominion, Adam, is no more Milton. Your dungeon stretching far and wide beneath. Id. Id. Id. Those put a lawful authority upon the stretch, to the abuse of power, under the colour of prerogative. L'Estrange. Disruption, as strong as they are, the bones would be in some danger of, upon a great and sudden stretch or contortion, if they were dry. Ray on the Creation. So the stretched cord the shackled dancer tries. Upon this alarm we made incredible stretches towards the south, to gain the fastnesses of Preston. Addison. What an allay do we find to the credit of the most L'Estrange. depends, would have been made out with reasons sufficient. VOL. XXI. Granville. STRETTO, in Italian music, is sometimes U |