Swiftsure, and afterwards in the Mary. After this, the nation being at peace, no opportunity was offered to this brave man of adding to those services which he had already rendered his country; and it is thought he died very soon after.-Campbell's Lives of the Admirals, vol. iv. STEAD, n. s. & v. a. Sax. rted; Goth. STEADFAST, adj. stod. Place; room; STEAD FASTLY, adv. position; support; STEAD FASTNESS, n. s. (hence the wooden STEADILY, adv. frame that supports a STEAD'INESS, n. s. bed;) aid: to fill the STEADY, adj. place of another; aid; help; support: steadfast is firm; fixed fast in place: hence firm of character; constant; resolute: steady is also firm; fixed; regular; constant: the respective adverbs and noun substantives corresponding. There fell down many slain, and they dwelt in their steads until the captivity. 1 Chron. v. 22. Be faithful to thy neighbour in his poverty; abide stedfast unto him in the time of his trouble. Ecclus. xxii. 23. 1 Peter v. 9. Him resist, stedfast in the faith. Their feet steady, their hands diligent, their eyes watchful, and their hearts resolute. Sidney. We are neither in skill, nor ability of power, greatly to stead you. Id. Such was this giant's fall, that seemed to shake This stedfast globe of earth, as it for fear did quake. Spenser. Your friendly aid and counsel much may stead me. So steadily does fickle fortune steer Congreve. Blackmore. The smallest act of charity shall stand us in great stead. Atterbury's Sermons. John got the better of his choleric temper, and wrought himself up to a great steadiness of mind, to pursue his interest through all impediments. Arbuthnot. In general, stedfastly believe that whatever God hath revealed is infallibly true. Wake's Preparation for Death. Steer the bounding bark with steady toil, When the storm thickens and the billows boil. Pope. STEAK, n. s. Isl. and Erse. styck, a piece; Swed. steka, to boil. A slice of flesh broiled or fried; a collop. Tatler. Swift. The surgeon protested he had cured him very well, and offered to eat the first stake of him. Fair ladies who contrive To feast on ale and stakes. STEAL, v. a. & v. n. STEAʼLER, n. s. STEA'LINGLY, adv. STEALTH. Pret. I stole; part. pass. stolen; Saxon reelan; Belg. stelen; right: the derivatives corresponding. by theft; take clandestinely, slily, or without How should we steal silver or gold? Gen. xlv. 8. Stolen waters are sweet, and bread eaten in secret is pleasant. Prov. ix. 17. Fixt of mind to avoid further entreaty, and to fly all company, one night she stole away. Sidney. They were divers motions, they did so stealingly slip one into another, as the latter part was ever in hand before the eye could discern the former was ended. Id. That he would steal away so guilty like, Seeing you coming. Shakspeare. Id. Othello. The most peaceable way, if you take a thief, is to let him shew what he is, and steal out of your company. Shakspeare. At time that lovers' flights doth still conceal, Through Athen's gate have we devised to steal. Id. In my conduct shall your ladies come, From whom you now must steal and take no leave. Id. The good humour is to steal at a minute's rest. -Convey, the wise it call; steal! a fico for the phrase! I feel this youth's perfections, With an invisible and subtile stealth, To creep in at mine eyes. Id. Id. Twelfth Night. The stealth of mutual entertainment With character too gross is written on Juliet. Shakspeare. STEAM, n. s. Sax. rreme. The smoke or vapor of any thing moist and hot. See below.. Scarcely had Phoebus in the gloomy east Got harnessed his fiery-footed team, Ne reared above the earth his flaming crest When the last deadly smoke aloft did steam. Spower Sweet odours are, in such company as there is steam and heat, things of great refreshment. Bacon. His offering soon propitious fire from heaven Consumed, with nimble glance and grateful stea Millon. Ye mists that rise from steaming lake. The dissolved amber plainly swam like a thin film upon the liquor, whence it steamed away into the air. Boyle. there O'er his warm blood, that steams into the air. Id. Which, were it not for plenty and for steam, These minerals not only issue out at these larger exits, but steam forth through the pores of the earth, occasioning sulphureous and other offensive stenches. Id. STEAM ENGINE. 1. STEAM ENGINE. Steam may justly be considered as the most important prime mover that the ingenuity of man has yet devised, and its utility to a commercial country like Great Britain must be sufficiently obvious. It has enabled us to support a proud superiority both in arts and manufactures, and, from the commercial advantages that have resulted, it has enabled us to fight the battles of freedom in every quarter of the globe. 2. Prior to entering into a detailed history of the steam engine, it may be advisable to furnish our readers with a brief view of the various prime movers that have been employed prior to the invention of this stupendous machine, and we shall thus be the better enabled to form an accurate estimate of its importance. We cannot better do this than by a reference to the introductory portion of Partington's Treatise on the Steam Engine. 3. From the most accurate observations it appears that the physical powers of the human race differ very widely, not only in various individuals, but also in different climates; the value of a an therefore, as a working machine, will not be so great beneath the torrid zone as in the mere temperate climate of Europe. This will serve to iliustrate the great advantage which our colonists, particularly in the West Indies, would derive from the more general employment of inanimate force; the day labor of a negro in the sugar countries amounting to little more than one-third of that performed by a European mechanic. 4. A laborer, working ten hours per day, can raise in one minute a weight equivalent to 3750 pounds one foot high, or about sixty cubic feet of water in the same time; while the power of a horse, working eight hours per day, may be correctly averaged at 20,000 lbs. Smeaton states that this animal, by means of pumps, can raise 250 hogsheads of water ten feet high in an hour. It is a well known fact also that men, when trained to running, are able on the average of several days being taken, to outstrip the fleetest horse; and yet it will be seen from the above statement that his force, if properly applied, is at least six times that of the most powerful man. 5. The use of water as an impelling power, both for the turning of machinery and other purposes connected with the useful arts, appears to have been known at a very early period. Vitruvius describes a variety of machines for this purpose, the earliest of which were employed merely to raise a portion of the fluid by which they were impelled. The most simple method of applying this element as a mechanical agent evidently consisted in the construction of a wheel, the periphery of which was composed of a number of float-boards. This, on being exposed to the action of a running stream, was afterwards employed to give motion to a variety of mills, and is at the present time employed in almost every species of machinery. 6. Among the most celebrated hydraulic ma chines we may enumerate the machine of Marly. This, when first constructed, appears to have produced one-eighth of the power expended, so that seven-eighths of its power were usually lost. This misapplied power has been injurious to the engine; and the wear it has occasioned has reduced the mechanical effect very materially. But this may be considered as an extreme case, and we select it merely as an instance of that total ignorance of the first principles of mechanics which characterised some foreign engineers of the last century. 7. It may, however, be advisable to examine the ratio of power expended in comparison with that of the effect produced in some of the most simple hydraulic machines; and, by this calcalation, the amount of friction, &c., may be accurately ascertained. Undershot water wheel Hydraulic ram. (This machine will make from twenty to 100 strokes per minute). Large machine at Chremnitz (each stroke occupying about three minutes). Power. Effect. 9.3 10 8. 8. But the water-mill, which is the usual machine employed, even in its most improved form, is far from being beneficial either to the agricul turist or the manufacturer. The former is injured by the laws which prohibit the draining of millstreams for the purposes of irrigation, by which much improvement is kept back that would otherwise take place; while the health of the latter, in the immediate neighbourhood of manufacturing districts, is much injured by the stagnant condition of the water which is thus unnecessarily dammed up. 9. Wind, which we may consider as the next substitute for animal power, appears to have been first employed to give motion to machinery in the beginning of the sixth century. The use of this species of mechanical force is, however, principally limited to the grinding of corn, the pressing of seed, and other simple manipulations; the great irregularity of this element precluding its application to those processes which require a continued motion. 10. A windmill with four sails, measuring seventy feet from the extremity of one sail to that of the opposite one, each being six feet and a half in width, is capable of raising 926 pounds. 232 feet in a minute; and of working on an average eight hours per day. This is equivalent to the work of thirty-four men ; twenty-five square feet of canvas performing the average work of a day laborer. A mill of this magnitude seldom. requires the attention of more than two men; and it will thus be seen that, making allowance for its irregularity, wind possesses a decided superiority over every species of animal labor. 11. To show, however, the great advantage which the steam engine, even in its rudest state, possesses over mere pneumatic or hydraulic ma chinery, we will now examine its effective force when employed in the working of pumps. It has been already stated that the machine of Marly, formerly considered the most powerful engine in the world, when first erected lost seven-eighths of its power from friction, and other causes; while the over-shot water-wheel, which can act only in favorable situations, produces nearly eight-tenths of the force employed. Now it is stated by Dr. Desaguliers that the atmospheric engine working at Griff-mine, nearly a century back, produced full two-thirds of effective force for the power employed; and this too at a comparatively moderate expense. We find, farther, that a hundred weight of coals burned in an engine on the old construction would raise at least 20,000 cubic feet of water twenty-four feet high; an engine with a twenty-four inch cylinder doing the work of seventy-four horses. From this it will be seen that a bushel of coals is equal to two horses, and that every inch of the cylinder performs nearly the work of a man. 12. An engine upon captain Savery's plan, constructed by Mr. Keir, has been found to raise nearly 3,000,000 lbs. of water one foot high with a single bushel of coals; while the best engine on Newcomen's principle will raise 19,000,000, and Mr. Watt's engine upwards of 30,000,000 lbs., the same height. If we add to the advantage gained by the employment of so cheap a prime mover, the vast concentration of force thus brought into immediate action, its value may easily be appreciated. 13. One of the largest engines yet constructed is now in action at the united mine in Cornwall; it raises 80,000 lbs. 100 feet high per minute; and to effect this enormous labor it only requires about thirty pounds of coal for the same period of time. 14. To the mining interests this valuable present of science to the arts has been peculiarly acceptable; as a large portion of our now most productive mineral districts must long ere this have been abandoned had not the steam engine been employed as an active auxiliary in those stupendous works. In the draining of fens and marsh lands this machine is in the highest degree valuable; and, in England particularly, it might be rendered still more generally useful. In practice it has been ascertained that an engine of six horse power will drain more than 8000 acres, raising the water six feet in height; while the cost of erection for an engine for this species of work, including the pumps, will not exceed £700. This is more than ten windmills can perform, at an annual expenditure of several hundred pounds; while, in the former case, the outgoings will not exceed £150 per annum. 15. To the mariner, also, the steam engine offers advantages of a no less important and novel nature than those we have already described. By its use he is enabled to traverse the waters, both against wind and tide, with nearly as much certainty, and, as the machinery is now constructed, with much less danger, than by the most eligible road conveyance. 16. The generation of steam forms a most important part of the subject under consideration. Indeed the whole power of the steam engine depends on the formation of elastic vapor produced from water varying in temperature from 212° of Fahrenheit's thermometer to about 300° of the same scale. This matter has been admirably discussed in the unfinished work by Dr. Birkbeck and Mr. Adcock, to whose pages we must now direct our readers' attention, as it contains a most masterly dissertation on the formation of steam. 17. Aqueous vapor, in its perfect state, is transparent and colorless, consequently invisible. We are chiefly accustomed to attend to it, when having partially mingled with the air, or having touched substances cooler than itself, it has become vesicular, and consequently visible. The moist white vapor, therefore, composed of an infinite number of vesicles or small globules, is not, as generally supposed, perfect steam, but steam which has been robbed of a portion of caloric. The consequence of this abstraction of caloric is the loss of the gaseous or elastic form, and is quickly followed by a complete restitution of the state of inelastic fluidity. The facility and suddenness, indeed, with which condensation, as this change is denominated, may be effected by different refrigerating means, is a property not less remarkable or important than elasticity, the energetic property which we have already mentioned. 18. Water exposed in an open vessel to the action of fire cannot, however great the heat applied, be made to indicate a higher temperature than that which first produces ebullition. Steam will be evolved in greater or less abundance, according to the heat applied, but throughout the process its temperature will continue the same as that of the water. Dr. Hooke directed public attention to this fact; but to Dr. Black is due the honor of having first minutely investigated the whole phenomenon. He discovered that, during the conversion of ice into water, a greater quantity of caloric disappeared than was indicated by the thermometer; therefore, reasoning from analogy, he was led to conclude that, as the difference between a liquid and a solid is ascribable to the fixation of caloric, so, most probably, an elastic fluid, such as steam, differs from a liquid, such as water, in consequence of the operation of the same cause. In endeavouring to ascertain this point, he compared the time of raising the temperature of a liquid a certain number of degrees with the time of evaporating it by the same influx of external heat, and found that the caloric existing in a latent state in steam which balances the pressure of the atmosphere was not less than 800°. Subsequent experiments performed by other philosophers seem to prove that the heat which disappears is here stated too low but it must be confessed that the results of the experiments on this interesting subject exhibit great discrepancies. Latent Heat of Aqueous Vapor. Black Ure. Southern Watt Clement Lavoisier Fahrenheit. Thompson 1016 19. Considering that the caloric producing these important changes was not immediately discoverable by the thermometer or the senses, Dr. Black gave it the name of latent heat. Subsequently it has been termed by Professor Pictet, with more propriety, caloric of fluidity, and caloric of vaporisation. from it was condensed with a crackling noise, and the water became heated. The water was constantly stirred, that the heat might be equally distributed, and the experiment was continued until the water had acquired from 70° to 90° of heat, which was generally in from four to six minutes. Afterwards the pan was covered with a disk of oiled paper, to prevent evaporation, which would have lessened the weight during the operation of weighing. The heat of the room, during the experiments, was generally about 56°. 23. Having so far completed the preparation, it became necessary, in order to obtain the greatest possible accuracy, to learn what quantity of heat had been absorbed by the pan. It was therefore made quite dry, and placed in a room of the temperature 40°; and in about half an hour, when it was supposed to have acquired the heat of the place, two pounds of water, of the temperature 76°, were poured into it. The result was 75° 30'. Then for every 35° 30′ with two pounds of water, or every 44° with two pounds and a half of water, half a degree must be allowed for the heat absorbed by the pan. 20. From the well-known ability and long experience of the late James Watt, we ought to conclude that the result of his experiments approaches very near the truth; more especially as it coincides with that of Southern, who in practical dexterity was very little, if at all, inferior to his highly ingenious and scientific friend. 21. It was in the course of the year 1781 that Mr. Watt tried experimentally to ascertain this point. He obtained a pipe of copper, onefiftieth of an inch thick, five feet long, and fiveeighths of an inch diameter in the bore, and, having bent the extremities in contrary directions, fixed one end steam-tight on the spout of a tea-kettle, from which the pipe inclined upwards, so that the other end was about two feet higher than the spout. In the upper end was fitted a piece of cork, having a hole about two- 24. Eleven experiments were made by Mr. tenths of an inch diameter, and a small piece of Watt, from which the latent heat of steam has quill introduced to keep the perforation open. been calculated according to the following examThe kettle was filled with water half way up the ple. The heat of the water in the pan at the spout, and the lid, being made tight with a pro- beginning of the experiment was 43.5, at the per lute, was securely held down by a piece of conclusion 89.5; so that, by the condensation of wood, reaching from the top of the centre of the the steam, the water in the pan gained 46° of lid to the under side of the handle. It was heat. The quantity of water in the pan at the placed over a fire and made to boil, and care was beginning of the experiment was 17,500 grains, at taken to allow the steam to escape, until such the end 18,260; therefore the effect was produced portion of it as condensed, no longer dropped by the condensation of a quantity of vapor equal from the end of the tube but returned by the to 760 grains. By multiplying the quantity of inclined part into the kettle. A tin pan, four water in the pan, at the beginning of the experiinches deep and six inches in diameter, was sup- ment, by the increase of temperature from the plied with two pounds and a half avoirdupois of condensed steam, and by the heat absorbed by water, then weighed with great accuracy, and the pan, we have 17500 × 46° × 0.5 = 81375; placed on several folds of flannel on a stand. and by dividing this product by the weight of This stand was made of sufficient height to al- condensed steam, and adding to the quotient the low the extremity of the cork in the upper end heat of the mixture, we have 81375760 + of the tube to be immersed in the water in the 89.5 1159-5, the sum of the sensible and pan. The water was nearly two inches and a latent heats. The sensible heat 212° being dehalf deep. A disk of strong paper, coated with ducted, leaves 947.5 as the latent heat of steam. linseed oil and dried, was fitted to the inside of the pan; and it was again accurately weighed. 22. When the end of the tube was immersed in the cold water of the pan, the steam issuing 25. In a similar manner, Mr. Watt determined the particulars of the other experiments, the results of which are exhibited in the following table: |