Engineering

"Shukhov is credited with the construction of some 200 towers using this method ..."

"[T]he diagrid form could support both the gravity loads and the lateral loads without requiring additional means. In comparison, the new skyscraper types that were under development at this time used a steel frame to support the gravity loads... while the central core provided the stiffness required to resist wind loads. Where additional resistance was required, it was usually the core that carried the bracing."

"The Shukhov towers tended to use much longer steel sections and overlap them at their crosspoints, rather than using the crosspoints as "nodes" in the fashion of later or spaceframe structures."

"Although the slender steel sections, when formed into the hyperbolic paraboloid shape, did undergo some bending, a diagrid shape emerges, using a combination of straight segments that are joined at their nodal points of intersection."

"Ref: S. Sabouri-Ghomi, M.H.K. Kharrazi, and P. Javidan, "Effect of stiffening rings on buckling stability of R.C. hyperbolic cooling towers," Thin Walled Structures, vol. 44, no. 2, pp. 152-158, 2006."

"191 of the Shukhov's Towers (from known near 200...) have been irretrievably lost during... the 20th century... [Some] towers were destroyed because their continued use for water supply has become impractical. To use them for another purpose... large investments were necessary."

"In 1829... Nikolai Ivanovich Lobachevsky published a disproof of Euclid's fifth or using the case of a doubly curved surface, thereby establishing non-Euclidean geometry."

"According to Elizabeth C. English, there was a direct connection between the mathematical discoveries of Lobachevsky and the structural explorations of"

"The first hyperboloid shaped cooling tower was introduced by the Dutch engineers and Gerard Kuypers and built in 1918 near having 35 meter height."

"The hyperbolic geometry has advantage of a negative which makes it superior in stability against external pressures..."

"The... structure is made of high-strength [cement,] Reinforced... Concrete... in the form of hyperbolic thin shell standing on diagonal, meridional, or vertical supporting columns and radial supports. The shell is sufficiently stiffened by upper and lower edge members."

"It is not known at what time chimneys began to be used. The writers of the 14th century seem either to have been unacquainted with chimneys, or to have considered them as the newest invention of luxury."

"That there were no chimneys in the 10th, 12th, and 13th centuries, has been presumed from the terms "ignitegium" [curfew] or "inpritegium" the curfew-bell of the English, and couvrefeu of the French; which seem to intimate, that the people made fires in their houses in a hole or pit in the centre of the floor, under an opening formed in the roof; and when the fire was burned out, or the family went to bed at night, the hole was shut by a cover of wood."

"[T]hough one or more expressions of ancient authors may appear to allude to a chimney, if the ancients were acquainted with the art of constructing, in mason-work, elevated funnels for conveying away the smoke, it must be allowed, when we consider the many proofs... to the contrary, that they were... extremely rare."

"It has frequently been a subject of inquiry, whether the ancients were acquainted with chimneys, or open fire-places. In the houses discovered at and , there are no chimneys; they all appear to have been warmed by furnaces and flues."

"How few persons are there who ever took the trouble to bestow a thought on the subject in question, though it is, in the highest degree, curious and interesting."

"The oldest certain account of chimneys, is in the year 1347. An inscription at Venice, records... a great many chimneys (molti comini) were thrown down by an earthquake."

"Things near us, and which are familiar to us, are seldom objects of our meditations."

"[W]e must never forget that it is the room that heats the air, and not the air that heats the room."

"The rays that are sent off from the burning fuel, generate heat, only when and where they are stopped, or absorbed, consequently they generate no heat in the air in the room, in passing through it, because they pass through it, and are not stopped by it, but, striking against the walls of the room, or against any solid body in the room, these rays are there stopped and absorbed, and it is there that the heat found in the room is generated. The air in the room is afterwards heated by coming into contact with these solid bodies. Many capital mistakes have arisen from inattention to this most important fact."

"[B]y a proper use of the two registers, together with a judicious management of the fire, the air in the room may either be made hotter, or colder;—or may be kept at any given temperature—or the room may be most effectually ventilated; and that this change of air may be effected, either gradually or more suddenly."

"The first chimney-sweepers in Germany came from , , and the neighbouring territories; and these for a long time were the only countries where the cleaning of chimneys was followed as a trade. Hence it is conjectured, that chimneys were invented in Italy."

"In building a house an air canal, about twelve or fifteen inches square, in the clear, and open at both ends, may be constructed, in, or near the center of each stack of chimneys; and two branches from this air canal, both furnished with registers, may open... one... into the fire-place, just under the grate, and the other over the fire-place, and near the top of the room, or just under the ceiling... The bottom of this air tube should reach to the ground, where it should communicate freely with the open air of the atmosphere..."

"Those who consider what an immense quantity of air is required to supply the current that sets up the chimney of an open fire place, where there is a fire burning, must perceive what an enormous loss of heat there must be, when all this expence of air is supplied by the warmed air of the room, and that all this warmed air is necessarily and constantly replaced by the cold air from without, which finds its way into the room, by the crevices of the doors and windows. But all this waste of heat, or any part... may be prevented by the scheme proposed, for if the air necessary to the combustion of the fuel, and to the supplying of the current up the chimney, be furnished by the air-tube, the warmed air in the room will remain in its places and as this will in a great measure prevent the cold currents from the crevices of the door and windows, the heat in the room will be the more equable, and consequently the more wholesome and agreeable on that account."

"It is really astonishing how little attention is paid to events which happen frequently, however interesting they may be as objects of curious investigation, or however they may be connected with the comforts and enjoyments of life."

"How many fire-places in close rooms have been cured completely of throwing puffs of smoke and dust into the room, merely by placing a register-stove in them? But there is surely nothing peculiar to a register-stove that could enable it to perform such a cure, but merely as it serves to diminish the width and heighth of the opening of the fire-place; and how much easier could this be done with marble, or other stone, or with bricks and mortar... [T]he openings of chimney fire-places are in general certainly too wide and too high and... there is no way of reducing them to a proper size... so cheap, or more effectual..."

"[C]ovings of... fire-places must be placed obliquely, and they must not be constructed of metal; and if the sides and back of the grate be constructed of fire bricks instead of iron, the fire will burn still brighter, and will fend off considerably more radiant heat into the room."

"Another cause... in bringing dust and smoke into rooms... is the great nicety with which the doors and windows are fitted in their frames, which prevents a sufficient quantity of fresh air from coming into the room, to supply a brisk current up the chimney. ...[A]ll the alterations in fire-places on the common construction, that have been recommended in order to improve them, must tend directly and very powerfully to lessen this evil; but nothing will so completely remedy it as lowering the mantle, and diminishing the width of the fire-place."

"If the under side of the mantle be left broad and flat... the cloud of dust or light ashes, that rises from a coal fire nearly burnt out, when... violently stirred... with a poker, striking perpendicularly against this flat part... must... be beat back into the room; but when the breast of the chimney is properly rounded off, the ascending cloud of dust and smoke more easily finds its way into the throat of the chimney, and is even directed and assisted in some measure by the warm air of the room that gets under the mantle and is going the same way."

"Another very common fault... in chimney fire-places, that have been altered on what have been called my principles, and which has a direct tendency to bring dust, and even smoke, into the room, is the sloping of the covings too much, and leaving the opening of the fire-place in front too wide. I have said, in my Essay on Chimney Fire-places, that where chimnies are well constructed, and well situated, and have never been apt to smoke, in altering them the covings may be placed at an angle of 135 degrees with the back; but... that they should never exceed that angle, and... bad consequences... must follow from making the opening of a fire-place very wide, when its depth is very shallow..."

"If in constructing or altering chimney fire-places, the rules laid down in my Essay on that subject are stricty adhered to, chimnies so fitted up will very seldom be found either to smoke, or to throw out dust into the room; and should they be found to have either of these faults, there is a remedy for the evil, as effectual, as it is simple and obvious: Bring down the mantle, and the throat of the chimney lower; and if it should be found necessary, reduce the width of opening of the fire-place in fronts and diminish the obliquity of the covings."

"...for chimnies that are apt to smoke, the covings should be placed less obliquely in respect to the back, than in others that have not that fault. But most... workmen... paid little attention to these distinctions and... frequently... and sometimes in fire-places that have been remarkably shallow... the covings have been placed at an angle even more oblique than that above-mentioned."

"I was much flattered on my return to England, in September 1798... to find that the improvements in the construction of chimney fire-places, which I had recommended in my Fourth Essay, published... 1796, were coming into use... It has been objected... that they sometimes occasion dust and ashes to come into the room when the fire is stirred. I have examined several fire-places... that have... that fault; but... found... their imperfections have arisen from faults in... construction. Either the grate has been brought out too far into the room, or the opening of the fire-place in front has been left too wide—or too high—or the workman has neglected to lower and to round off the breast of the chimney—or... several of these faults... together..."

"I hope likewise to be able to show in an Essay on Cottage Fire-places, which I am now preparing for publication, that three quarters, at least, of the fuel which cottagers now consume in cooking their victuals, and in warming their dwellings, may with great ease, and without any expensive apparatus, be saved."

"When the throat of a chimney is situated very high up above the mantle, and especially when the mantle and breast of the chimney, or the wall that reposes on the mantle, are very thin, workmen who are employed to alter chimnies, setting about the work with their minds strongly prepossessed with what they consider as the leading principle... that the throat of the chimney should not be more than four inches wide, they are very apt to bring the grate too far forward. In dropping their plumb-line from the breast of the chimney, they do not reach up high enough into the chimney, but take a part of the breast, where it still goes on to slope backwards, for the bottom of the perpendicular canal of the chimney. They also very often commit another fault, not less essential... in neglecting to bring down the throat of the chimney nearer to the fire, when... too high."

"I never view from a distance, as I come into town this black cloud which hangs over London without wishing to be able to compute the immense number of chaldrons of coals of which it is composed; for could this be ascertained, I am persuaded so striking a fact would awaken the curiosity, and excite the astonishment of all ranks of the inhabitants; and perhaps turn their minds to an object of economy to which they have hitherto paid little attention."

"The enormous waste of fuel in London may be estimated by the vast dark cloud which continually hangs over this great metropolis, and frequently overshadows the whole country, far and wide; for this dense cloud is certainly composed almost entirely of unconsumed coal, which having stolen wings from the innumerable fires of this great city has escaped by the Chimnies, and continues to sail about in the air, till having lost the heat which gave it volatility, it falls in a dry shower of extremely fine black dust to the ground, obscuring the atmosphere in its descent, and frequently changing the brightest day into more than Egyptian darkness."

"Though the saving of fuel which will result from the improvements to the forms of Chimney Fire-places here recommended will be very considerable, yet I hope to be able to show in a future Essay, that still greater savings may be made, and more important advantages derived from the introduction of improvements I shall propose in Kitchen Fire-places."

"It is likewise very important to "round off the breast of the chimney;" though this... is very often intirely neglected... by workmen..."

"[I]n the countries of modern Europe, the use of stoves prevail throughout the north; while in France and Great Britain, open fires are used. In the warm countries of Italy and Spain, there are very few chimneys, and the only method usually practised of tempering the cold, which is sometimes severely felt, is to burn charcoal in portable brasiers."

"The intention of this contrivance is that the winds and eddies which strike against the oblique surface of these covers may be reflected upwards instead of blowing down the Chimney.—The invention is by no means new, but it has not hitherto been often put in practice.—As often as I have seen it tried it has been found to be of use; I cannot say,. however, that I was ever obliged to have recourse to it, or to any similar contrivance; and if I forbear to enlarge upon the subject of these inventions, it is because I am persuaded that when Chimnies are properly constructed in the neighbourhood of the Fire-place little more will be necessary to be done at the top of the Chimney than to leave it open."

"Count Rumford was the first to extensively study inside-fireplace proportions. ...Deep-set fuel beds produce more smoke... since there is scant combustible air at the back... [T]he rate of smoke emission increases proportionally to the depth of the firebox, especially in the early stages of firing."

"The breast of a chimney should always be rounded off... beginning from the very front of the lower part of the mantle, and ending at the narrowest part of the throat of the chimney, where the breast ends in the front part of the perpendicular canal of the chimney. If the under surface of the mantle is flat and wide, it will be impossible to round off the breast properly; and that circumstance alone renders it indispensably necessary, in those cases, to alter the mantle, or to run under it a thinner piece of stone, or a thin wall of bricks, supported on an iron bar, in order that the breast of the chimney may be brought to be of the proper form, and the throat of the chimney may be brought into its proper situation."

"In lighting a coal fire more wood should be employed than is commonly used, and fewer coals; and as soon as the fire burns bright, and the coals are well lighted, and not before, more coals should be added to increase the fire to its proper size."

"I am not the inventor of any of those stoves or grates, that have been offered to the public for sale, under my name."

"Count Rumford's conclusions about the relationship between the chimney throat and effective draft have yet to be scientifically questioned. The throat opening should... constrain the effluent, so that it will be forced to... a speed high enough to discourage down drafts."

"Those [grates] whose construction is the most simple, and... the cheapest, are beyond comparison the best, on all accounts.— Nothing being wanted in these Chimnies but merely a grate for containing the coal, and in which they will burn with a clear fire;—and all additional apparatus being, not only useless, but very pernicious, all complicated and expensive grates should be laid aside, and such as are more simple substituted in the room of them."

"[T]he height to which the new back and covings ought to be carried... will depend not only on the height of the mantle, but also, and more especially, on the height of the breast of the Chimney, or of that part of the Chimney where the breast ends and the upright canal begins.—The back and covings must rise a few inches, five or six... higher than this part, otherwise the throat of the Chimney will not be properly formed;—but I know of no advantages that would be gained by carrying them up still higher."

"And in the choice of a grate, as in every thing else, beauty and elegance may easily be united with the most perfect simplicity.—Indeed they are incompatible with every thing else."

"[T]he form of the breast of the Chimney is... of... great importance... The worst form it can have is that of a vertical plane, or upright flat;—and next... worst... is an inclined plane.—Both... cause the current of warm air from the room, which will... sometimes find its way into the Chimney, to cross upon the current of smoke, which rises from the fire, in a manner, most likely to embarrass it in its ascent, and drive it back.— The inclined plane which is formed by a flat register placed in the throat of a Chimney produces the same effects; and this is one reason, among many... which have induced me to disapprove of register stoves."