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I TOLD you before that four things are necessary in addition to good judgment for one who wishes to practice the art of casting well. The first is to make the moulds and to have the furnace well made, the wood of a good kind, dry and seasoned, and the material disposed to melt. I have given you enlightenment on all these in detail, and on the last point as well, as you can see in the discussion on the alloys of metals where, among other things, I told you a good deal about those of copper. Therefore I wish to say but little about them in this chapter, but in order to follow the order promised you, I tell you that when you can, and if the labor or expense does not displease you, you should always alloy the whole quantity of the metals that you wish to put into one work and should make them into cakes of one kind. For, in addition to being more conveniently arranged in the furnace and mire easily handled, they all melt at one time and with much less work than they would if they were in pieces of different kinds. It is necessary to give corruption to copper, for if you decided to melt fine copper by itself in a reverberatory furnace your soul would burst before you had any honor therefrom. Then, if you wished to cast a fine thing from it, it would not succeed because it is dot fluid, on account of its viscosity; and if it should succeed, it would be all full of holes, like a

Jan 1, 1942

CALAMINE is one of the semiminerals that have great similarity to the metals. It is a very heavy mineral earth of a yellowish color. It is found in Germany near the lead mines and in Italy in a mountain between Milan and Como. It is also found, as I have heard, in other places, as at Fosini in the territory of Siena. I believe that it is almost certain that some exists there because there are many other kinds of minerals there- about, although none is mined there in these times. But this does not mean that it could not be mined or that there is not some there that is real. Someone says that he med to melt what he could find with copper [36v]

Jan 1, 1942

By Archibald Macmartin

THE Königin-Marien-Hütte is the only works in Germany where the Bessemer process is carried on by the direct method. The Besserner plant there, is arranged after the true English type, and the only resemblance to the Swedish mode of procedure is the dispensing with the use of spiegeleisen at the end of the "blow." In a new department of the establishment, started within three years, each of the converters is turned by means of a very neat and compact reversible engine, the steel shaft of which is an endless screw, which turns against the oblique cogs of a large wheel attached to the shaft of the vessel. An advantage which this arrangement possesses over the ordinary English hydraulic arrangement, is the fact that the endless screw suffices to turn the vessel, in either direction, any number of complete revolutions; while even the latest American improvements, so clearly explained to us by Mr. Holley at the opening session of this meeting, do not secure even one complete revolution without changing the angle of inclination of the hydraulic piston. In the endless screw arrangement, there being no limit to the working of the motor in either direction (no return-stroke necessary), the vessel can always, unless outside reasons demand the contrary, be turned around to any desired position by the shortest cut, whether backwards or forwards. Also, the diameter of the cog-wheel attached to the vessel can be made sufficiently great to avoid all unevenness of motion. In the old department the motive-power still continues to be hydraulic. If reports be true, the new department produces spiegelized steel, for the manufacture of all-steel rails. But the old department is still,' as from the beginning, devoted to the production by the direct method of steel for steel-headed rails. The most remarkable fact connected with this direct steel is the ease with which it welds to the iron' of the rail-packets, although no borax or other fluxing agent is used to facilitate the welding. It is very rarely that an exception occurs, and an ingot or a charge is discarded by the rail-mill. The mixture of pig-iron used for the production of this steel is melted in cupolas of very interesting construction (not to be de

Jan 1, 1874

COAL is perennially -a subject of major interest at. Pittsburgh, but during the week of Nov. 19 to 24 it was especially to the fore because nearly two thousand persons gathered to take part in the second of the international conferences organized by President Baker of the Carnegie Institute. From the opening session on Monday morning when those attending were welcomed by President Baker and T. P. Gaylord, president of the Chamber of Commerce of Pittsburgh, until the party returned from the Clairton coke ovens on Saturday. afternoon, there was something going on all the time, and usually three sessions were in progress at once.

Jan 1, 1928

UNDER the same justification that I spoke to you in the preceding chapter on crystal and some other gems, I can now speak much better and with much greater reason of glass, since it is one of the effects and peculiar fruits of the art of fire. Every product that is found [41v] in the interior of the earth is either stone or metal or one of the semiminerals, and glass, as is seen, resembles them all, although in all respects it is dependent upon art. Therefore it seems to me that before coming to the discussion of the arts themselves, I must treat of this very beautiful composition created by art and number it with the semiminerals. Thus in this chapter I shall speak to you of glass, not as a proper semimineral, nor yet as a metal, but as a fusible material that is almost made mineral by art and by the power and virtue of fire, born from the speculation of good alchemistic savants, through whose efforts it imitates. the metals on one hand and the transparency and splendor of gems. on the other. Certainly it is a very beautiful thing and one that should not be left buried in silence, in consideration first of how great a thing art has been, able to discover, and then because its beauty makes it such a pleasing thing for making drinking. glasses and an infinite number of other ornamental things that satisfy the desires of man. I shall begin, then, by telling you, to the credit of the alchemists, how I believe that this thing was found through their desire to make gems; for when they could not bring them to perfection (as also happened with the metals) they made this beautiful and attractive product, glass. However, Pliny says that it was found by chance in Syria at the mouth of the Belus River by certain merchants who were driven there by the fortunes of the sea and forced to stop and disembark there for a time in order to eat. In cooking the food they saw the rocks of that place converted into a flowing, lustrous material. And as they thought about this, it seemed beautiful to them, and when they went away they carried some stones and plants with them. Thus they gave beginning to glass making. But now leaving this discussion it does not matter how it may have been discovered, whether by merchants or by ingenious alchemists. Art is that which has given it being, through many experiments and by addition

Jan 1, 1942

OCHRE is a semimineral composed by Nature of earth and a tincture of yellow caused by a fumosity of lead ore. By itself it is a material without any [38] metal, although when it is used in smelting it helps to melt the harsh and sour ores of metals. I do not know that it has any other use, except to painters. Bole is also a red viscous earth which has a very astringent and drying nature. It has no very apparent smell or taste, and I think that the cause of its redness lies in the fumosities of iron ore, for it is a companion to this and is found in its mines. It is an efficacious medicine against any poison and in this capacity has an action like terra sigillata* or perhaps better. In

Jan 1, 1942

MANY are the salts produced. by Nature in various regions and parts of the world, as Pliny shows in his History. Likewise, many are the differences among things that are salty and from which salt can be extracted, as, for instance, all the lyes from any kind of ashes and the urine of all animals. But because these are not things that give men the useful elements necessary to life, I shall omit speaking of them in detail with the exception of some of the more notable ones, and I shall tell you that I find that men proceed in only two ways in order to have a sufficiency for their needs. One is that of extracting it from the salty waters of the sea itself, or from springs, with a certain technique [34v] adapted to the places, either by congealing or by evaporation; and the other is that of mining it from the earth. The latter salt is clear and beautiful, and it is mined from mountains, already made by Nature in the form of stone without the aid of art. All these salts have more or less efficacy* according to the fineness or coarseness of their earthy elemental mixture, and according to the provinces and places where they are found generated. All are of an earthy

Jan 1, 1942

By G. Vibert Douglas

It has long been recognized that there are considerable difficulties connected with the physical and chemical explanation of shoots of ore. The literature of Mining Geology has frequent references to this subject; but the reasons given for the actual location of primary ore-shoots have been very tentative. In practice, the geologist or miner depends to a great extent on sampling and assaying to determine the boundaries of profitable ore within the mineralized zone. An ore-shoot is a portion of a mineralized zone which has a sufficient concentration of valuable minerals to make it ore. Ore deposits have been classified according to many schemes. There are classifications based on morphology and on genesis. However, it is also possible to classify hypo-gene hydrothermal ore-bodies in terms of ore-shoots or vice versa. A.-Ore-deposits in which the whole of the mineralized zone is ore, which is the same as saying that the ore-shoot extends throughout the mineralized zone. An example of this type of deposit would be the pyritic mineralization of Rio Tinto. B.-The second type would comprise those deposits in which the ore-shoots bear some relation to the geological structure of the area: all deposits in which 'bonanzas' occur in folds in the zone, at the intersection of veins along certain fault (or joint) features and other such controls. There are a great many examples of this type: (a) The Rhodesian copper lodes, where Bancroft and Gray have pointed out the association of the shoots of ore with drag folds. (b) A similar association has been pointed out by Faribault for some of the gold veins of Nova Scotia, e.g., Mount Uniacke. (c) The great bonanza of the Comstock lode in Nevada. C.-Deposits in which the localization of ore has been effected by the chemical character of the wall-rock. Examples of this type are the Fahlbands of Scandinavia, and the 'indicator' deposits of Ballarat, Australia. D.-Lastly, deposits in which there is apparently no structural and no chemical control.

Jan 1, 1934

HAVING previously told you about lodestone, azure, emery, and manganese, things that perhaps belong more properly to the stones than to the metals, the desire has come to me to describe rock crystal as well and, with this, some of the better-known gems, although they are things that are not classified with metals, as far as I know, or even with the serniminerals. In truth, they are neither one nor the other, but they are stones and have the nature of stones. But let them be what they may, in order to avoid straying from the subject we have begun, we shall say that they have mineral properties in their species, as for instance, in respect to their colors. It would seem an error to me if, while I am giving you information on so many other useful things, I did not give you this as well, if for no other reason than because it is a fine accomplishment for a gentleman to have some knowledge concerning gems. Thus since I have proposed to do this, beginning to speak of crystal, I tell you that it is a lustrous, transparent, and limpid stone, composed by Nature with a predominance of wateriness. Thus, contrary to the order of natural things, it has been believed by many that Nature has generated it of pure water by means of a powerful and continuous coldness that always exists in those mountains and places where it is found, for the waters and snows can never melt there because of the great cold. They have tried to prove this opinion of theirs by saying that crystal still retains the nature of frozen water, and that this is. shown not only in its appearance but also in the fact that, like ice, it floats without sinking to the bottom when it is put in water. They also say that it is customary to put it under the tongues of the thirsty on account of the, coldness and moistness which it gives, and that it quenches the dryness of their thirst. But even if all these things were true, as they are not, they do not upon consideration bring us to the conclusion that it is water, because the diamond and the beryl would do the same. Therefore it does not seem to me credible [391 that it is as they claim, for it is a stone generated as such by Nature. And then, if this were true in those places where it rains often and many snows are formed, and these should freeze and never melt but

Jan 1, 1942

SULPHUR is a very well known mineral and apparently is produced in many places. It is engendered from an unctuous earthy and powerfully hot substance so that it is considered among experienced workers to bear a resemblance to the element of fire. This is called by these same men the masculine seed and the prime agent of Nature in the composition of metals. Because of its great dryness and heat it has, as experience shows, affinity with fire, which is easily introduced in it when brought near. And once introduced the fire is quenched only with difficulty before its unctuousness is wholly consumed. Although it shows itself to us of such a hot and dry nature, we must not think that sulphur is a substance so pure that it can stand by itself or that in order to attain its form it has no need of its portion and part of moisture like every other mixture. This is shown to us by its easy fusion, in which it resembles the metals. This thing is found in many places and in many varieties of color; some are white, others yellow and orange, and some others between gray and black. They also say that some red is found. It does not occur in that arrangement of veins like other minerals, but most liberal Nature makes whole mountains of it as is seen in the Aeolian islands, [26] near Sicily, in Etna or Moncibello which is the island of Sicily, at Pozzuoli, in the territory of Rome, in the Sienese domain at San Filippo, and in many other similar places. It is a substance that has a very strong odor and is most unpleasant to smell. It is very fixed in its substance so that it is never corrupted by time, by boiling, or by the moisture of water. For although it may stand in water a long time it never becomes soft nor does it ever decrease or increase in weight. It is brittle and easily crushed very fine. It is said that a trace of garlic rubbed on the mortar helps anyone who wishes to reduce it to impalpability. Its ores have a form more like earth than like stone although they some¬times have the color of a certain soft rock. The places where it is found are easily recognized by the great odor that they give out and by the very hot baths that often spring forth near it. What I have already told you about quicksilver that is contrary to the

Jan 1, 1942

By F. W. Bloecher, A. M. Gaudin

Using an adsorption-column technique the partition of dodecylamine between quartz and water has been determined at concentrations ranging from 0.5 to 4000 mg per liter. The adsorption varies as the square root of the concentration. Attachment of dodecylamine to quartz is reversible. The amount adsorbed in a flotation operation giving almost complete recovery is under 5 pct of the amount required for a monolayer.

Jan 4, 1950

LEAD and tin mixed together make an alloy through an attachment of natural affinity which they have with each other, so that when they are mixed it is difficult to recognize by the sight which one it is, if the essences of their qualities are not surpassed by more than half. If, indeed, one can be recognized, it is the tin which gives off a certain sharp odor to the sense of smell, besides having a greater hardness and whiteness. The best of these is the one that is the purest in its kind. In the alloy of tin it is the one that is the whitest and hardest, or, when it is bent or some thin end of it is held tightly by the teeth, is heard to crackle as frozen water does. Because this happens more with this than with other metals, I do not wish now to inquire into it. It is enough that it be a sign for recognizing when tin is pure or mixed. Pewterers say that it should be joined in alloy with lead and that it is better for working when it contains four or six pounds to the hundred because it makes it softer to the hammer and more fluid in casting. But I do not like to hear this, even if all they say is true, for I see that the tin that comes from England, when worked as well as in cakes that show it to be pure, is much more beautiful and better in all works than is that made in Venice. And I believe that it is not better for any work when mixed than when pure, except for the advantage of the master who, if he does nothing else, sells lead that is worth little for tin that is worth much. I find that when mixed it serves in only two things. One is when it is wished to make a solder for copper, for use when it is not worth while to solder the bottoms and large pieces of vessels with low-grade silver as should be done. The other is when master potters calcine it in order to make glazes and to apply white to their vases. I consider lead to be useless in all other works of any kind of metal, since it unites with none of the other metals of good company except tin.

Jan 1, 1942

SINCE I have mentioned the art of alchemy in. many parts of this treatise of mine, especially when 'came to the description of the practice of various operations,* I do not here intend to argue as to whether it may be called true or not. But in case it is true, inasmuch as it is seen in operation to be a result dependent on the actions and virtues of fires, I should not pass by in silence without speaking at all of this art here, nor would I wish to do so, especially since I think that you do not really know what it is except in so far as common report is heard everywhere to the effect that whoever carries it to completion makes silver and gold with it. Because of this belief, many seek it with much time, labor, and expense, as I know you have often heard related, if not elsewhere, by me in the chapter on gold that I have written in this volume. Now do not think that I wish to teach you this art here, for I am one of those who do not know it. Therefore I shall tell you here, so that you may know more, only. that those workers who so eagerly follow after and seek it proceed by just two pathways. One is that which takes its enlightenment from the words of the wise philosophers, by means of which they think to attain it. This they call the just, holy, and good way, and they, say that in this they are but imitators and assistants of Nature, indeed, manipulators and true physicians-of .mineral bodies, purging them of superfluities and assisting them by augmenting their virtue and freeing them from their defects. In this way they sometimes proceed to corrupt these bodies in order to be able to separate the elements they contain so as to reduce them, if possible, to their primary materials, as they call them, or sometimes they convert them into new substances by means of this art or by adding another spirit different from the first one. Thus they seek in this way to bring these materials to a certain point of corruption or to a separation of elements, or to remove or add spirits to things, or to make coarse materials subtle and sometimes to make subtle materials coarse. Therefore, as you can understand, these persons, with bridle broken, run a circular track night and day, without ever having rest; and surely I do not know whether anyone has ever arrived at the desired goal. Nevertheless, even though the goal of this art were emptiness, as many

Jan 1, 1942

IT is necessary that all men who wish to bring things to a certain end should think of the agents needed to attain this. Now whichever one of the above processes you wish to use you must consider the nature of the material and see whether it is disposed to render what you wish to extract. Then you must see whether you have the other agents sufficiently powerful and proportioned to attain this result, for if the things were not in harmony your work would be vain and very laborious. Therefore, if you should wish to make waters or oils by way of distilla-

Jan 1, 1942

IN discussing the art of the goldsmith, it is apparent that it is an art requiring skill. He who wishes to be acclaimed a good master therein must be a good universal master in several arts, for the different kinds of work that come to his hands to be done are infinite. Those who work in gold and silver must outdistance all other craftsmen in learning and achievement to the same degree that their materials outdistance other metals in nobility. Therefore, it is necessary first of all to be a good designer, because design is the key that opens the doors not only to the goldsmith's craft but to all others. Then it is necessary that he understand melting and that he know well how to work with a hammer and how to use flat gravers and burins in engraving, as well as files and chisels. He must also possess certain secrets that are needful to the art, which in truth are parts of alchemy, such as softening gold when it is brittle and raw, coloring it when it has little color, soldering, enameling, working in niello, blanching, gilding, and an infinite number of things which must all be known in detail. But above all he who wishes to do this art well must be very patient in working, must know how to mould and how to proceed with the melt and with the file, hammer, chisel, or other implements for bringing his gold or silver work to the final state which he plans. He must also have good judgment in gems and know well how to recognize every [134v] good or defective quality they possess, and to distinguish the false gem from the true, either when set or when unmounted, as there is need; also how to value them both in buying or selling and in satisfying others who seek his appraisal. He should also be experienced not only in the technique of melting but also in the methods of assaying, parting, refining, cementing, and the like, and still many others. But if I wished to tell you of every part

Jan 1, 1942

HAVING told you of the practices of the arts involving other metals, I wish to tell you also of the practice of that of tin.* Indeed, since this is an easily melted metal, in common use for the utensils which are made for human needs, it is an art known not only to skilled men but also almost to children, wherefore I could proceed with- out telling of it. However, besides the production of plates and bowls and many other dishes for eating from and keeping things in, this embraces two other arts, both of which you should know about because they are useful and beautifid. One of these is the art .of making the letters with which books are printed, and the other is that of making the sheets from which organ pipes are built. The vessels, as perhaps you have seen, are cast one by one in moulds made of white tuff. Several pieces fastened together are then put on the iron axle of a wheel rotated by hand, and [138v] they are turned with a slightly bent tool which has a cutting edge. In this way they are made thin and of a good shape. Then they are polished with a piece of linen cloth and a little powdered tripoli, and thus they are finished. The letters for printing books are made of a composition of three parts of fine tin, an eighth part of black lead, and another eighth part of fused marcasite of antimony.t The desired quantities of these metals are melted

Jan 1, 1942

THE task of the smith who works in iron is very laborious, indeed far more so than that of the coppersmith just described. For he also handles heavy weights continually, and stands constantly erect be- fore the fire of the forge, since the hardness of the iron cannot be softened except by means of heating and boiling it well. In this place he continually moves his body, now thrusting the iron into the heart of the fire with large thick tongs, now removing it to look at it and to put sand, tuff, or other earth over it, now putting on fresh charcoal, now moistening and slowing down the fire, and now cleaning it. Finally, while the iron is hot

Jan 1, 1942

By Angus Hellawell

The application of the common tangent principle to free energy - composition surfaces is considered. It is shown that the construction requires that single phase surfaces on either side of a two phase volume must always exhibit the same sign of curvature - contrary to that shown in many published phase diagrams. In general, these curvatures will be such that the surfaces are mutually concave towards the more stable phase. A number of examples are discussed.

Jan 1, 1991

BEFORE I go any farther, I wish to show you the different kinds of guns, as I have been able to understand them from the finished works, for no one is found to have written or spoken of this. To my knowledge, it is not universally known who was the inventor of this horrible and fearful instrument. It is believed that it came from. Germany, discovered by chance at least three hundred years ago, according to Cornazzano, * from a crude and small beginning like the printing of letters. I believe, .indeed it seems to me certain, that guns evolved from the effect of powder, and then the forms were varied and changed according to the desires and different abilities of those who made or wished to use them. †

Jan 1, 1942

IT may perhaps seem to you that I have deviated from sequence by having entered into the narration of this arrangement of the bellows, but, although they are not furnaces or vessels for containing the melts, they are essential agents for bringing to port the bark of your labors. Returning to our regular pathway, and supposing that, besides making the moulds, you have melted and cast not only statues and bells but also guns, it is true that a certain procedure is required in order to finish them. For this you should have the moulds full, and they should have come out very well, for in truth reason does not allow that they turn out otherwise for one who uses precaution. [II2V] Then you have taken your casting from the pit and have freed it of clay. Since I have told you nothing beyond this, do not be dismayed if you see the castings so rough and in a form that scarcely shows what they really are, for I wish to open up part of the way into the great labor of finishing them so that it may seem to you that you have been somewhat helped by me. Therefore, when it is a gun, first see that the iron spindle that has been placed in the middle of the core is taken out. You can do this easily by striking the heel of the core, especially if the spindle had first been covered with ashes, hemp, or a little rope. Then saw off the feeding head above the mouth, using either a dun steel saw with tiny straight teeth that has been tempered with oil or some other fat, or a hay sickle whose edge is gently hit by a little hammer. Then have the clay that is attached to the curls or other bronze parts lifted away with a chisel. Then with a scouring brush and water uncover the emblems, coats of arms, borders, and cornices that you made as ornaments. Striking it with a hammer, push inwards every superfluous bit of bronze. Finally, having cleaned the bronze by washing, scraping, and cutting away every bit of clay, strike its surfaces gently with a large hammer and thus make it very smooth. Likewise finish the mouth and all its cornices as exactly and completely as possible with files and any other instrument that serves best. Then take a long, powerful tool that has some steel on the point, made like a chisel and somewhat bent, or with three points like the iron blade

Jan 1, 1942