Engineering

"It may be converted into vapour at a temperature approaching a red-heat, and may be distilled unchanged; it is a perfect conductor of electricity and an excellent conductor of heat. Its most marked difference from the common run of metals was its extraordinarily low specific gravity."

"It is frequently stated that Davy was enabled to isolate the metals of the alkalis because of the large and powerful voltaic battery which he had at his disposal in the Royal Institution. This is not correct. The battery he employed was of very moderate dimensions, and not by any means extraordinary in power. It was the success he thus achieved that caused the large battery, which is probably referred to, to be constructed, by special subscription, in 1809."

"Although no great stress can be laid on numbers so obtained, they serve to indicate that Davy had not yet obtained the pure metal."

"Other metals, like lead and mercury, did not appear to burn; but on heating them they gradually lost their metallic appearance, and became converted into calces. This operation was known as . In the act of burning or of calcination phlogiston was expelled. Hence metals were essentially compound: they consisted of phlogiston and a calx, the nature of which determined the character of the metal. By adding phlogiston to a calx the metal was regenerated. Thus, on heating the calx of or of with , or , or wood, metallic zinc or lead was again formed. When a candle burns, its phlogiston is transferred to the air; if burned in a limited supply of air, combustion ceases, because the air becomes saturated with phlogiston."

"From the first discovery of the production of metals from rude ores, to the knowledge of the bleaching liquor, chemistry has been continually subservient to cultivation and improvement."

"Scheele discovered in 1781; and soon after a metal was extracted from it by Messrs. Fausto & Juan José] D' Elhuyars."

"The relations of the common metals to the bases of the alkalies and earths, and the gradations of resemblance between the bases of the earths and s, point out as probable a similarity in the constitution of all inflammable bodies; and there are not wanting experiments, which render their possible decomposition far from a chimerical idea."

"Arnald of Villa Nova... was one of the earliest European inquirers who attended to chemical operations. ...[H]e firmly believed in the transmutation of metals; the same opinions are attributed to him and to Geber; and he seems to have followed the study with no other views than those of preparing medicines, and attempting the composition of the philosopher's stone."

"[M]etals remained the alchemists' chief concern... they seemed in their own way alive, whereas the calces (s) from which they were manufactured crumbled to dust and looked like cinders. Theory at once suggested a natural analogy. The metal was formed from the calx by the incorporation of or spirit; and this theory of metal-formation long remained in favour, being revived around 1700 as the 'phlogiston' theory. The central problem about metals was to identify the volitile constituents which combined with the calces to form the finished metal. For a long time, the status of quicksilver was ambiguous... resembling much more the volatile reagents which corrode metallic surfaces: mercury, in fact, forms an amalgam with other metals, and is even capable of dissolving gold... So the Alchemy of Avicenna classed mercury as a 'spirit' rather than a 'body'..."

"The magnetism as exhibited in iron is an isolated phenomenon in nature. What it is that makes this metal behave so radically different from all other materials in this respect has not yet been ascertained, though many theories have been suggested. As regards magnetism, the molecules of the various bodies behave like hollow beams partly filled with a heavy fluid and balanced in the middle in the manner of a see-saw. Evidently some disturbing influence exists in nature which causes each molecule, like such a beam, to tilt either one or the other way. If the molecules are tilted one way, the body is magnetic; if they are tilted the other way, the body is non-magnetic; but both positions are stable, as they would be in the case of the hollow beam, owing to the rush of the fluid to the lower end. Now, the wonderful thing is that the molecules of all known bodies went one way, while those of iron went the other way. This metal, it would seem, has an origin entirely different from that of the rest of the globe. It is highly improbable that we shall discover some other and cheaper material which will equal or surpass iron in magnetic qualities."

"Mercury doesn't contribute its valence electrons readily to the [electron] soup. The thinner soup can't bind the mercury atoms together very strongly. Mercury atoms easily slip past and away from each other. Heat easily overcomes the weak binding between mercury atoms, and mercury boils and melts at lower temperatures than any other metal. Because the valence electron soup is thinner for mercury, its electrical and thermal conductivity are poor."

"[T]here are not really 2-dimensional metals because conventional metals, for physics reasons... don't really like to be in the 2-D state, and most of them immediately oxidize anyway... So by discovering ... we created materials which are 2-dimensional metals. So we... closed the gap in existing the series of materials."

"Theophrastus, the successor of Aristotle, ...says, in the beginning of his book on fossils, 'stones are produced from earth, metals from water.' ...Theophrastus is perhaps the best observer among the ancients, whose works are in our possession, and [his] theories... cannot be considered as an unfavourable specimen of the theoretical physics of the age."

"Beccher, ...after having studied with minute attention, the operations of , and the phænomena of the kingdom, formed the bold idea of explaining the whole system of the earth by the mutual agency and changes of a few elements. And by supposing the existence of a vitrifiable, a metallic, and an inflammable earth, he attempted to account for the various productions of rocks, crystalline bodies, and metallic veins, assuming a continued interchange of principles between the atmosphere, the ocean, and the solid surface of the globe, and considering the operations of nature as all capable of being imitated by art."

"While Paracelsus was pressing his doctrines on all sides, and endeavouring to lead chemistry into a new channel, another, Agricola, was quietly at work among the mines of Saxony, utterly indifferent to all but the advance of his science. It is to Agricola's systematic observations that we trace the beginnings of the science of mineralogy. In metallurgy, also, he was a pioneer, the first to give a clear and succinct account of the preparation of many metals. He taught the condensation and purification of sulphur given off during the roasting of many s, the separation of silver from gold by means of nitric and sulphuric acid, the preparation of such bodies as salt, , and saltpetre on a large scale. The apparatus described by Agricola and employed by him for the and testing of ores were still in use at the end of the eighteenth century. Agricola stands out solitary among the men of his time as one pursuing chemistry from pure love of the science; his work had no other aim than the increase of knowledge."

"Iron yields to certain degrees of beatings or repeated pressure; its impenetrable molecules, purified by man and made homogeneous, disintegrate; and, without being in fusion, the metal no longer has the same virtue of resistance. Marshals, locksmiths, tool makers, all the workers who constantly work this metal then express the state of it by a word of their technology: "The iron is retty!" they say, appropriating this expression exclusively devoted to hemp, the disorganization of which is obtained by retting. Well, the human soul, or if you will the threefold energy of body, heart, and spirit, is in an iron-like situation, as a result of certain repeated shocks. It is thus with men like hemp and iron — they are retty."

"One worker on one of the supports... either manually or with a trowel distributes the mortar over the chicken wire... Simultaneously, another worker from within the room... holds the mortar which is applied from the outside with a metal float or trowel in order that the mortar does not fall. Once this operation is completed, the required finish is applied both from the outside and the inside."

"The export of into Italy was strictly forbidden; but aluminium was almost the only metal that Italy produced in quantities beyond her own needs. The importation of scrap iron and into Italy was sternly vetoed in the name of public justice. But as the Italian metallurgical industry made but little use of them, and as steel billets and were not interfered with, Italy suffered no hindrance. Thus, the measures pressed with so great a parade were not real sanctions to paralyse the aggressor, but merely such half-hearted sanctions as the aggressor would tolerate, because in fact, though onerous, they stimulated Italian war spirit. The League of Nations, therefore, proceeded to the rescue of Abyssinia on the basis that nothing must be done to hamper the invading Italian armies. These facts were not known to the British public at the time of the election. They earnestly supported the policy of the sanctions, and believed that this was a sure way of bringing the Italian assault upon Abyssinia to an end."

"Tradition has it that not only concerned himself with the unification of Egypt but also with the control of the river: to him is attributed the first damming of the Nile, the digging of dikes for agricultural purposes and indeed the first attempt to control and apportion the waters of the river. The wealth of Egypt was thus, with , based upon its agricultural output. However, unlike Mesopotamia, the Egyptians had on their doorstep a number of mineral resources that they were able to exploit with little effort, including copper ores, gold and a wide range of rocks suitable for building and the making of a wide variety of ornaments. [S]hortly before the year 3000 metallurgists made a discovery that was to transform the entire "industry." ...by mixing a small quantity of tin ore with the copper ores when... smelted... they discovered the alloy . The occurrence of tinstone... does not occur in the same type of deposit as do the ores of copper, but rather, [near] veins of gold. ...Thus tinstone ...may well have been noticed during washing for gold... finding that the little black lumps of ore were relatively heavy, presumably made various attempts at smelting them until they arrived empirically at a suitable alloy... [T]he effect is to reduce the melting point... they had a far more fluid metal that was much easier to cast. ...the quality of casting improved dramatically."

"Aristotle had considered metals to be formed by the combination of moist and dry exhalations, and in the Jabirian works these... are... vapours of mercury and sulphur. The cause of the different metals was the... quality of the sulphur... The term sulphur ...as a component of metals probably referred to a volatile combustible material to which no... substance corresponded exactly. Likewise mercury... may... have been... an approximation to the other volatile liquid component of metals. ...The notion that metals contained a combustible principle persisted, and... provided the inspiration for the phlogiston theory."

"My invention shows a new product which helps to replace timber where it is endangered by wetness, as in wood flooring, water containers, plant pots, etc. The new substance consists of a metal net of wire or sticks which are connected or formed like a flexible woven mat. I give this net a form which looks in the best possible way, similar to the articles I want to create. Then I put in hydraulic cement or similar bitumen tar or mix, to fill up the joints."

"Nothing can vex the Devil more Than the name of him whom we adore. Therefore doth it delight me best To stand in the choir among the rest, With the great organ trumpeting Through its metallic tubes, and sing: Et verbum caro factum est! [And the Word was made flesh!] These words the devil cannot endure, For he knoweth their meaning well! Him they trouble and repel, Us they comfort and allure, And happy it were, if our delight Were as great as his affright!"

"Mercury as a liquid metal is capable of dissolving other metals and forming metallic solutions. These are generally called 'amalgams.' The formation of these solutions is often accompanied by the development of a large amount of heat—for instance when and sodium are dissolved... but sometimes heat is absorbed, as... when is dissolved. ...[T]he solution of metals in mercury is accompanied by the formation of definite chemical compounds of the mercury with the metals dissolved. ...[I]n many cases such compounds have undoubtedly been obtained, and their existence is clearly shown by the evident crystalline structure and characteristic appearance of many amalgams."

"Sonorous metal blowing martial sounds, At which the universal host up sent A shout that tore hell's concave, and beyond Frighted the reign of Chaos and old Night."

"The history of science may be described as the breaking down, and the crumbling away, of artificially constructed barriers. All the great men of science have been famous wall-breakers. ...It is worthy to remark that the central conception of the alchemists ...was the unity of natural phenomena. ...[T]heir arguments would be somewhat as follows—Plants grow from seeds ...animals become larger, stronger, and more complete ...the plant may well be called more perfect than the seed, and the full grown animal more perfect than the immature ...both plants and animals grow, come to their prime, and decay; and there are degrees of perfection in the animal and vegetable worlds. Now—we may suppose the argument of the alchemist... minerals and metals and all inanimate things should grow, and change, from less perfect to more perfect forms; as there are degrees of perfectness and dignity in among all living things, so... among all things; some metals disappear in acrid liquids, and... are... easily worn away, they are readily melted and burnt to ; but some other metals are not swallowed up by corrosive liquids, nor... worn away with ease, nor readily changed in fire; there are evidently noble and base metals, perfect and imperfect metals; and as the less perfect seed... produces the more perfect plant... rendered yet more perfect by cultivation, so the imperfect metals change slowly into... more perfect, and this... can be hastened by man's art and devices. ...[L]iving things are more perfect that inanimate things ...[M]uch more must changes from immature to mature forms be constantly proceeding from dead things like minerals and metals ...[I]t is probable that the plasticity of the minerals and metals will be greater ...hence ...it will be a comparatively easy thing to grow a noble metal like gold from ignoble metals like and copper, although it is impossible to change one kind of animal into another or one sort of plant into another ... A vague conception of the unity of nature... led to little accurate knowledge..; all that could be done was to perform a vast number of inaccurate and incomplete experiments, and to state the results in loose and slipshod language of the vague but sonorous hypothesis which prompted the experiments. And so although the hypothesis postulated the unity of nature there was no unity in the experimental results... collected to support the hypothesis. ...A man who sets out to discover what is must endeavour to put aside all his notions of what ought to be; it is only when he has gained a solid foundation of verified and accurate facts that he may venture to make a definite guess concerning the cause ...but unless he makes clearly stated guesses ...scientific hypotheses—he will remain a mere collector of half facts ..."

", The Story of the Chemical Elements (1897) pp. 16-19."

"The whole work was done under conditions of great mental excitement. His cousin ,.. his assistant, relates that when he [Humphrey Davy] saw the minute globules of the quicksilver-like metal burst through the crust of potash and take fire, his joy knew no bounds; he actually danced about the room in ecstasy, and it was some time before he was sufficiently composed to continue his experiments. The rapidity with which he accumulated results after this first feeling of delirious delight had passed was extraordinary."

"Some of the alchemists had discovered that a metal gained, not lost, weight by . This was known as far back as the sixteenth century. It had been pointed out by Cardan and by Libavius. Sulzbach showed that such was the case with mercury. Boyle proved it in the case of tin, and Rey in that of lead. Moreover, as knowledge increased it became certain that Stahl's original conception of the principle of combustion as a ponderable substance he imagined, with Becher, that it was of the nature of an earth was not tenable. The later phlogistians were disposed to regard it as probably identical with . But even hydrogen has weight, and facts seemed to require that phlogiston, if it existed at all, should be devoid of weight."

"[E]early chemical discoveries led to the pursuit of alchemy, the objects of which were to produce a substance capable of converting all other metals into gold: and an universal remedy calculated indefinitely to prolong the period of human life."

"The processes supposed to relate to the transmutation of metals, and the , were probably first made known to the Europeans during the time of the ..."

"had been used to tinge glass in in the sixteenth century; but the metal was unknown till the time of Brandt, and this celebrated Swedish chemist discovered it in 1733."

"The properties of , which was announced as a peculiar metal by Kaim in 1770, were minutely investigated by Scheele and Bergman a few years after."

"Platina had been brought into Europe and examined by Lewis in 1749 and in 1803, Descotils, Fourcroy, and Vauquelin announced a new metallic substance in it; but the complete investigation of the properties of this extraordinary body was reserved for Messrs. Tennant and Wollaston, who in 1803 and 1804 discovered in it no less than four new metallic substances, besides the body which exists in it in the largest proportion, namely, iridium, osmium, palladium, and rhodium."

"By researches, the commencement of which is owing to Messrs. Nicholson and Carlisle, in 1800, which were continued by Cruickshank, Henry, Wollaston, Children, Pepys, Pfaff, Desormes, Biot, Thenard, Hissinger, and Berzelius, it appeared that various compound bodies were capable of decomposition by electricity; and experiments, which it was my good fortune to institute, proved that several substances which had never been separated into any other forms of matter in the common processes of experiment, were susceptible of analysis by electrical powers; in consequence of these circumstances, the fixed es and several of the earths have been shewn to be metals combined with oxygene; various new agents have been furnished to chemistry, and many novel results obtained by their application, which at the same time that they have strengthened some of the doctrines of the school of Lavoisier, have overturned others, and have proved that the generalizations of the Antiphlogistic philosophers were far from having anticipated the whole progress of discovery."

"Before the middle of November he had obtained most of the leading facts. In a letter dated November 13th he tells W. H. Pepys—"

"He had observed that although potash when dry is a nonconductor, it readily conducts when it becomes damp by exposure to air, and in this state "fuses and decomposes by strong electrical powers.""

"It would seem from his description of its properties that the potassium he obtained was most probably alloyed with sodium derived from impure potash. Potassium is solid up to 143° F.; but, as Davy subsequently found, an alloy of potassium and sodium is fluid at ordinary temperatures. ...When the potassium was exposed to air its metallic lustre was immediately destroyed, and it was ultimately wholly reconverted into potash by absorption of oxygen and moisture."

"The "basis" of potash at 50° F. was a soft and malleable solid with the lustre of polished silver."

"This sense of taboo was based on a range of arguments against research on albedo modification that have been raised by the broader scientific community, including: 1. the so-called moral hazard issue, that is, the possibility that research on climate engineering could be perceived as an implicit legitimization, and thus reduce the motivation for mitigating anthropogenic emissions; 2. the concern that reducing temperatures by albedo modification could distract from other impacts of a fossil-fuel-based economy and the resulting CO2 emissions, such as ocean acidification; 3. the “slippery slope” concern that research into understanding the potential effectiveness could cascade toward the development and deployment of the techniques under investigation; and 4. contention about the perceived “techno-fix” approach to address environmental challenges, that is, the notion that technology-caused problems can simply be fixed with more and better technology."

"A wide range of techniques has been proposed for increasing the planetary , ranging from painting surfaces white to placing mirrors in orbit between the Earth and the sun."

"[G]iven the balance of results of model studies over the last decade... and the challenging directions that this implies both for future research and also for sociopolitical aspects, especially public perception and the development of good governance principles, we have to conclude that the overall verdict is still out. The responsibility still resides with the scientific community to conduct research and engage in the broader dialogue in a responsible way, so that whatever the outcome, historians will hopefully look back and conclude that it was indeed of value—and in that sense a moral imperative—to begin carefully investigating this topic... Perhaps this will already be clear by the time of the next special section like this one, which, following those in 1996 and 2006, should be due in 2026."

"[T]he problem of possible changes in climate may be better solved by cooperative application of modern technologies rather than by international measures focused on prohibitions."

"[H]is belief... a reduction in the cost of building large structures in outer space could be achieved by delivering the necessary materials from the moon... [H]e presupposed the existence of the necessary industrial plants on the moon, but the end result would be a thousand-fold reduction in the cost of building large structures in space."

"Greenhouse warming of the Earth due to human activities is a possibility, moreover one for which mitigative/remedial actions of the types proposed here can be at once deliberate and effective. In contrast, Ice Age-severity cooling... that have occurred quasi-periodically many times during the last 1.2 million years, is a practical certainty. Moreover, a several-decade duration cold snap of Ice Age Maximum temperature-drop is known to have occurred in the Northern Hemisphere with essentially no warning during the last interglacial period, under precursor climatic conditions only slightly warmer than the present-day one."

"Oberth... began the book Men in Outer Space: New Projects for Rockets and Space Travel... written in the style accessible to the general reader. ...Published in 1955 in German, it was translated into English, French, Italian, Dutch, and even in Croatian! ...Oberth's new book was indeed "cosmic," and this gave it a cardinal distinction from his classic book of the 1920s. ...A supplemental chapter ...is devoted to "s," a theme which occupied Oberth all his life. A short description ...is already present in the 1923 book. In 1929, when he published his fundamental work, Ways to Space Travel, he included a much more comprehensive description... in the chapter... "Space Stations." ...[A]lmost the entire chapter is devoted to space mirrors. In the 1954 book... a new varient... is presented. Eventually in Bucharest in 1978, an entire book (in German) was devoted to this theme. ...[T]he primary purpose for the space mirror would today be called an ecological one ...At the time ...there was ...no robotics technology, and he assumed all the work after ...erection ...would ...be carried out manually by astronauts."

"The glass may be launched to the shield location by a . A number of studies have indicated that mass drivers are feasible and economical for launching unmanned payloads from the lunar surface. If the glass sheet is sufficiently flexible it may be formed into sheet on the lunar surface and launched in rolls."

"[A] giant net (similar to a trawl) would be erected in outer space, constructed in a hexagonal mesh pattern. This net would be stretched out and a tension sufficient to rotate the entire net would be maintained by . The rotation would be begun by special rockets and... continue because it was in a vacuum. The diameter of each hexagon would be about 10 kilometers, and the entire mirror would have a circular disk shape with a diameter of about 100 to 200 kilometers. Within each hexagon, a round mirror approximately 10 kilometers in diameter, would be installed. ...[Each] single mirror would be capable of being [independently] tilted... initiated by... electric s."

"The shield may also be transparent and simply scatter the visible photons away from the Earth. ...A glass shield may act as a prism to deflect the sunlight away from the planet in accordance with ."

"An ideal opaque shield would scatter the Earth bound solar energy into diffuse infrared energy."

"can be formed into glass for either a transparent or opaque shield."