Tartaric Acid
An organic acid found in grapes, the tamarind, unripe berries of the mountain ash; and in small quantity in some other plants. In grape-juice it is present as a bitartrate of potash or cream of tartar, and it forms on the insides of wine-casks as a hard crust. The acid is obtained from the bitartrate by the action of chalk and sulphuric acid. When pure, its crystals are colorless and transparent, and in dry air they remain permanent. Mixed with bicarbonates of the alkalies it forms the soda-powder for effervescing drinks. When heated to redness in a covered crucible it forms the mixture of carbon and carbonate of potash known in the laboratory as black flux. When it is calcined with twice its weight of water, white flux is formed. SEE FLUX.
Technical Education for the Moulder.--We are told that technical education has for its object the training of persons in the arts and sciences that underlie the practice of some trade or profession, and embraces all kinds of instruction that have direct reference to the career a person is following or preparing to follow.
Owing to the gradual breaking up of the apprenticeship system, the ranks of the skilled foundrymen have been woefully reduced, and must continue to be indifferently recruited from among the foreign workmen who arrive here, if something be not done at once to check the evil. The question naturally arises at this crisis, Will the technical schools furnish the remedy? A thorough apprenticeship means such instruction in the trade as will give the young man an intelligent knowledge of all its branches; but this means that he shall be gradually advanced, step by step, and receive special instruction and practice in each department--a system entirely at variance with what are now considered to be the best means for rapid production. Under the old regime the boy received the fullest share of attention from his so-called "master," and it was reasonable to expect that he would be taught all that it was possible to teach, if the true spirit of the indenture were carried out. The "master" was bound to teach the boy all of his trade, omitting nothing. Under such circumstances every detail of the craft was learned, and on the termination of the contract he who was the obedient apprentice rightfully became the competent journeyman. If we look carefully into the subject we shall discover that production on a large scale has been the means of inaugurating a new system of dividing labor. Now, this system works advantageously to the employer, because, keeping a boy constantly on one particular branch of work, he naturally becomes more expert, and the total output of his work is proportionately increased thereby. The result of this new order of things has been to limit the boy's ideas of moulding to that particular part upon which he has spent his effort, to the exclusion of the greater part of what constitutes the full and legal measure of a journeyman's knowledge of the trade. In other words, he is launched into the business world a thoroughly incompetent moulder; and there are to-day hundreds of such graduating in the large pump, architectural, and stove corporations, in the foundries of which boys are kept at one job throughout the whole course of their servitude.
This apparently unpreventable condition of things has, more than any other cause, created the necessity for technical education of a kind that will, if possible, not only train the minds of our youth in the arts and sciences underlying their trade, but also practically make good the deficiencies of such an incomplete apprenticeship.
The difficulties in obtaining a sound technical education are, we admit, very great; and it would be unreasonable to expect that the theoretical and practical could ever attain to the highest degree of excellence in the one individual. The requirements in each case are necessarily of a different order, each demanding special and distinct lines of thought and action--for which reason the likelihood of such a union is rendered very doubtful. It must be conceded, however, that to the acknowledged advantage of a technical training, as affecting the moulders themselves and the welfare of the foundry generally, we must add the certain improvement that must take place in the work produced, resulting from the superior and better-trained intelligence of those who would be benefited by such instruction.
Some writers have been uncharitable enough to suggest that this superior knowledge, once gained, would generate in the workman a dislike for the ruder and more active parts of his trade. The writer of this hastens to correct all such ill-timed and unwise conclusions. We have always found the opposite to obtain in every instance: the greater the intelligence of the workman, the more diligent he becomes. His superior knowledge imparts a stimulus to the efforts he puts forth; and the result of his labors, being manifestly in advance of his less intelligent fellow-craftsmen, meets with substantial and well-merited approval. This, of course, is the legitimate reward, and constitutes a fitting accompaniment to the inner satisfaction he enjoys. But, rest assured, the moulder possessing these superior attainments will not long remain in the ranks: he will undoubtedly be called into higher spheres of usefulness, where opportunities will be afforded for a fuller and more effective display of his talents.
The fact that it is a matter of some difficulty to obtain competent foremen for some of the mammoth foundries now being erected is made more apparent every day. In order that there should be nothing lacking in the management of such concerns, proprietors have in many instances been compelled to engage the services of an educated superintendent, whose chief business is to overlook the foundry generally, and see that every action of the more active foreman is directed in channels that run in harmony with known physical laws. Why the moulders of to-day are incompetent for such positions is attributable to two causes--the first being the altered condition under which foundries are now being conducted, rendering it simply impossible for the ordinary workman to acquaint himself with all the details connected with the trade. The second cause will be discovered to be a natural result of the rude awakening experienced in the foundry interest generally to the fact that they were wretchedly behind every other branch of the iron industry in the application of modern improvements, mechanical and otherwise, and in their pardonable haste to redeem themselves appliances have been added in such number and kind and with such precipitancy as to change the nature of things in the foundry altogether.
The suddenness of these late innovations has been almost bewildering in its effect upon the old systems of management; but if, during the time this forced exodus of old-fogyism was taking place, the foreman had been supplementing his daily shop practice with evening instruction in some well-conducted technical school, there is no doubt that he would have been equal to the emergency, as the knowledge there obtained of the new requirements would have qualified him to adequately fill the position, even with the increased responsibilities consequent in the changes spoken of.
We regret to notice that (excepting one or two noble examples) as yet there does not seem to have been any genuine effort to make the foundry department in most of the existing schools equal to the requirements. We need never expect these schools to give the requisite instruction for overcoming the difficulties above described while the present system of choosing instructors is maintained. The latter-mentioned dignitaries are, as a rule, very deficient in all that pertains to a correct knowledge of founding; nor need we wonder at this when we consider that the salaries offered for such instructors are usually much below the remuneration a good journeyman moulder receives at the foundry. The sooner this phase of the subject is thoroughly investigated by the authorities in these matters the better it will inevitably be for all concerned.
We have reason to believe that, if more latitude were given the professors in selecting instructors of founding, a much better state of things would prevail. They would naturally look about for the most suitable person, and offer such inducement as would be likely to secure the worthiest men for candidates. As matters appear to stand at present, the trustees of these institutions, who, we may surmise, are as a rule unacquainted with the actual requirements for such a position, allow feelings of prejudice and mistaken notions of economy to prevail; and as a consequence, instructors are appointed without reference to capacity, their chief recommendation being the diminutive compensation claimed for such valuable (?) services. Foundry instructors should be unmistakably acknowledged masters of the art of founding; and their education should, at least, measure up to a standard that will enable them to explain in an intelligible manner every operation involved in the production of all kinds of castings, as well as the concomitant qualities of an executive order. The moulder whose career has been a marked success in the foundry, and who has graduated in the sciences directly bearing on his trade at one of the schools, is undoubtedly one of the very best candidates for the position of instructor of founding at the technical schools; and none of the very questionable reasons above mentioned should be allowed to operate against the appointment of such candidates. This degree of qualification can only be attained by men who, having realized the necessity of such attainments, have diligently studied the theoretical as well as practical part of their trade. It is in this very particular that the present technical-school system offers perhaps the best opportunity yet known for the aspiring founder to advance himself.
A highly reprehensible feature in some of these institutions is the placing of one person to instruct in two or more departments. To expect that one teacher, no matter how extensively read he may be in the text-books, can correctly teach several trades is preposterous. Such a system, if persisted in, must assuredly result in failure and disgrace. The engineer, no matter how profound and extended his general knowledge may be, would naturally shrink from the task of instructing a moulder in all the niceties and perplexing phases connected with the art of founding, as would also the intelligent boiler-maker, if he were asked to instruct a class in modeling; and yet it is a fact that such impossibilities are attempted, with what results we may readily infer.
We confess to being somewhat amused when we read and hear the constant complaint about "the inaccuracies of the average moulder;" but we happen to know that the slipshod methods of working, so prevalent in some places, is mainly owing to the fact that ignorance of the real necessities of the foundry on the part of the management has tended to the withholding of such appliances as would insure the accuracy looked for. Consequently, for lack of encouragement, the moulder has been forced to invent some makeshift for the occasion; hence it is common to hear the expression, "Anything will do for the foundry."
The spirit of contempt for foundry needs and conveniences has at last received its death-blow in the manufactories, as we have endeavored to show; but, strange to say, it has again risen phoenix-like in the schools--the very last place we should have expected to find it. Pass through the several departments of the general order of technical schools, and you will find that the equipment is on a grand scale for almost every section except the foundry. The engine-room is a model of perfection, as it ought to be; the fitting, turning, and general machine-rooms are elegantly provided with the most modern machinery; the forging department has all that could be desired to make it of real service, while the carpentry and other wood-working sections are lacking in nothing to make instruction effective. Last, but by no means least in importance, is the foundry, where we find almost everything narrowed down to a mere shadow of what ought to exist in this department if it is to be of any practical benefit whatever.
The young men from our foundries, who are anxious to supplement their daily practice with such instruction as might very readily be given in these schools, are instantly provoked to laughter when they first contemplate the meagre and insufficient means usually provided for illustrating the art of founding--in some instances not going beyond the antiquated sand-tub of our respected fore-fathers, with a few small flasks which bear no resemblance whatever to those used in actual practice. This, in conjunction with the very indifferent cupola arrangements, constitutes in some schools what is considered sufficient for foundry instruction. Such means are undoubtedly inadequate for any other purpose than to furnish occasional amusement to the general order of students, who have not the remotest idea of ever engaging in the business of founding.
These excellent institutions may be made invaluable to the moulder, if the regularly constituted authorities can be brought to grasp the situation. No general treatment will answer his case fully; there must be a special and clearly defined course of instruction, excluding all subjects that have no direct bearing on the subject of founding. This special education should include chemistry, because by its aid much of that which is enigmatical in foundry practice, and which to the unlearned is still a positive mystery, can be made plain and intelligible. A knowledge of this science would so change the order of things as to make what has heretofore been a monotonous drudgery an extremely agreeable occupation. Another important result of this increased intelligence would be a sensible diminution of the failures and loss incident to practice founded on nothing more than the merest chance. The need for a more extended application of the science of chemistry is constantly being forced on the founder in some way or other. Chemists whose occupation has been in line with the foundry are now telling us that the methods usually adopted for ascertaining the nature and quality of pig iron are untrustworthy, and must ultimately give place to the more scientific mode of analysis. The latter method, they claim, will enable the founder to determine the mixture from the analysis furnished by the makers, before it is charged into the cupola, to a certainty; because, having a knowledge of the properties common to the several elements present, he will be able to blend the several brands in such proportions as will produced the desired qualities in resultant mixture.
A practical demonstration of this and other theories could be readily made in the technical schools by successive mixtures melted in crucibles; the formula for each mixture could be changed, and a record kept of the changes caused by the varying quantities of the several elements entering into each test. The physical results, such as hardness, fluidity, chill, shrinkage, strength, etc., could be satisfactorily determined by Keep's Testing-machine--a knowledge of the use of which should be taught in every school of technology. Some natural philosophy as well as mathematics must enter into this special course, in order that the laws relating to combustion, pressure, and numerous other kindred subjects, but very imperfectly understood by the great army of moulders, may be more generally known among them. All this will tend to sharpen the inventive faculties, and give zest and energy to minds which must otherwise remain comparatively dormant.
While it must be admitted that the general equipment for the technical school cannot possibly equal in magnitude or variety that required for large foundries, it cannot be denied that to be of any practical service whatever all such equipment should contain all the elements suitable for a practical demonstration and thorough illustration of every department of the trade by the instructor.
The cupola, for instance, should not be smaller than 24 inches inside diameter, plain in design, but provided with the best furnishings in ordinary use. The reasons for suggesting a plain cupola are that more of that kind are in use than of any other, and comparisons with improved specimens can be more readily made; also, that they are better for experimental purposes. Instruments for ascertaining the amount of friction, pressure, etc., in blast-pipes and all the phenomena connected with melting should be provided, and their use fully explained by the instructor. The cupola would be the place where the instructor could in the most effective manner teach sound views, based upon actual practice and experiment, regarding the economy of fuel; what is meant by perfect combustion, and how it is brought about in the cupola; the importance of supplying the exact quantity of air to secure best results, and how to correctly measure the same, etc.
The reverberatory furnace need not be of greater capacity than is absolutely necessary for demonstrating its use for the purpose of melting cast iron and brass. The different principles of melting in direct contact with the fuel, as in the cupola, and of melting by exposing the metal to the action of the flame, as in the reverberatory, could be effectively illustrated and explained by actual practice. Subsequent tests, chemical and physical, would reveal differences caused by the two methods of melting, as well as furnish practice and experience in a branch of the business which has for some time been considerably undervalued and neglected.
Crucible-melting for brass, cast iron, and steel should be taught thoroughly. For brass an ordinary air-furnace of the common type should be provided, in order to clearly demonstrate the different modes of melting with a natural draught and a force one, the latter being the style of furnace to be provided for melting cast iron and steel. The common brass-furnace with natural draught may be converted into a blast-furnace suitable for melting cast iron or steel in crucibles by simply making the ash-pit door air-tight and introducing the blast therein at a pressure of about three ounces. This would serve to illustrate the ordinary class of crucible-melting, and should be supplemented by a regenerating-furnace of the latest type, suitable for exhibiting the improved methods of obtaining extreme heats from inferior fuels, etc. The uses to which the crucible can be put for experimental purposes are too numerous to mention here, and no instructor who understands this thoroughly will fail to make good use of the opportunities they offer.
If moulding is to be taught in the technical school, castings must be made undoubtedly of such kind and dimensions as will best serve to bring out distinctly all the underlying principles which govern the art. Objections are made to this view of the matter on the ground of expense principally, but this should not be allowed to prevail if we are earnest in our desires to see this great object succeed. Here, again, we notice that no complaint reaches the surface on that score about any other department than the foundry. It cannot be that the objectors are so ignorant of affairs as to think the business of founding of minor importance in the great metal industries. Every day furnishes evidence conclusive that the foundry ranks as high, if not higher, than any other department in importance, and that under intelligent and skilful direction it may be made even more valuable than has yet been dreamed of.
Allow the foundry instruction in these schools to occupy the position it is justly entitled to, and we shall not be long in discovering that our fears were without foundation. Our young men will immediately avail themselves of the opportunities offered for obtaining information beyond that afforded in the daily routine of the shop. They will attend the night-schools, because, owing to the diversified exercises chosen, there will always be something novel and instructive to attract the attention and secure their steady attendance upon the studies enforced.
Suitable objects for the purpose of illustrating the methods of moulding in loam, green-sand, dry sand, and core making of all descriptions could be readily obtained from the neighboring manufactories and city works of castings of a duplicate character in constant demand. Drawings could be furnished by said firms to which patterns, core-boxes, and sweeps could be made by the students in that branch under direction of their own instructor, aided by the instructor of founding. The patterns would furnish admirable practice of a genuine kind, and when complete would be moulded from in the foundry. The castings could then be bored, turned, or milled in the machine department to drawings supplied and afterwards delivered and paid for in the regular way of trade, thus furnishing serviceable practice to several branches of students, as well as being a source of revenue to the institution. Take, for instance, an ordinary sewer-head for the city, for which castings there is always a steady demand. These castings could be made very serviceable as examples for illustration. A suitable set of flasks should be made to mould it in green-sand vertically, the core to be made in the pattern used. The same pattern could be also used as an example of bedding-in, using a cope only to cover with. Another pattern could be made in halves for the same casting with flasks to suit for casting horizontally. In this case a dry-sand core could be used, also a green-sand one on a horizontal arbor. Lastly, the centre spindle and sweep-boards could be brought into requisition for moulding this casting, exclusive of pattern or flasks, forming both the outer and inner surfaces with bricks and loam.
The above-described examples, simple as they seem, afford scope for a considerable amount of ingenuity, and almost every branch of the moulder's art is called into practice to produce these castings in the several ways described.
The instructor should be qualified to teach all the branches of moulding enumerated above; and most assuredly his sins will find him out if he is in any sense deficient, there being no one at hand able to furnish the talent wherewith to cover his own shortcomings--something of altogether too frequent occurrence in the foundries.
The importance of having men of ability and judgment as instructors will be apparent, even to the uninitiated, when they consider that all the necessary tools and their appurtenances requisite for these dissimilar operations must be devised by him in such variety and design as will not only answer present needs, but serve also as standard models of their kind, to be used for the purpose of illustration when it is desired to inculcate high-class methods of construction in the minds of the students.
Another very suitable object which might be chosen as a study in all the branches of moulding is a twenty-four-inch steam-cylinder, to be obtained from one of the large pump and engine works. This casting, in addition to the opportunities presented for moulding under altered circumstances, offers the further inducement that subsequent boring and finishing in the machine department would reveal at once any imperfections arising from either faulty moulds or unsuitable iron. The construction of such a mould entirely in green-sand, to be cast horizontally, would call forth some very excellent practice in the arrangements for pouring, in order to obtain clean castings in the bore; also to practically demonstrate the greater nicety and more delicate workmanship displayed in producing castings this way than are required for the same job in dry sand.
The latter useful and effective style of moulding can be very ably illustrated by such a cylinder. Different modes of finishing and closing, in fact all the chief operations demanded for dry-sand work of greater magnitude, may be this one illustration be made exceedingly plain.
As in dry sand so in loam: the requisite equipment for the production of such a casting in loam could be made so as to represent a facsimile of that required for moulding the largest cylinders for the government cruisers. Firms making a specialty of ship-propellers would be willing to accept castings produced at these institutions at their market value; consequently this very interesting and highly instructive phase of the moulder's art could be learned more thoroughly in the school than in the foundry. The sizes chosen for this purpose might range from two feet to five feet in diameter, with varying pitches to accommodate the obliging firm, who would regulate them according to the stock generally carried. Here, again, we have unmistakably good practice for the pattern-making department in providing the necessary moulding-boxes with the single-wing attachment for moulding small wheels in green-sand sectionally--a method which exacts the nicest manipulation and requires considerable practice before perfection is attained. For casting wheels in dry sand the instructor would teach how to construct the requisite sets of flasks for moulding from a fixed spindle and one wing at a time, in flasks secured to a foundation-plate, using separate copes for the upper side of the blade. Practice of this class develops the constructive faculties, and expands the mind beyond the limits of an ordinary moulder's experience. The larger wheels would make good examples for loam-work, for, in addition to the practice afforded in manipulating moulds with the spindle and sweep-board, the right use of the angle-board could be effectively explained. A 5-foot wheel would be large enough for a practical illustration of every principle involved in producing one 15 feet diameter by the same method. The value of these instructions in propeller-moulding would be considerably enhanced by procuring an old casting about 3 feet 6 inches diameter, from which to mould one occasionally in green-sand: by bedding in the sand with the upper tips of the blades level with the floor, forming the joints at each blade, and lifting out the hanging-sand with lifters hooked on the bars of an ordinary 4-foot-square flat cope. This is a very useful class of experience, and much needed almost everywhere.
The above-described methods of moulding propeller-wheels serve as excellent illustrations of the several modes of moulding of which they are representative, the first being a specimen of sectional moulding applicable to work other than wheels; the second shows how the centre spindle may become of almost universal use in producing certain classes of castings from a simple section of the whole pattern, commonly provided. The angle-board used for forming the blade in loam is a study in itself. Since its introduction for the above purpose, very many similar objects are thus formed by the moulder, and considerable pattern-making saved, as well as cost for the mechanical contrivances formerly used. For instance, grooved drums, formerly moulded in loam by revolving two or three grooves from top to bottom of the outside cope by means of a central threaded spindle, are now formed by one revolution of a full-length sweep-board travelling on a guide corresponding to one turn of the thread desired.
A 12-inch ordinary socket-pipe 10 feet long, such as are used for city purposes, could without difficulty be obtained. By moulding these in the several ways to be described, considerable knowledge of an extraordinary kind is to be gained. By preparing a set of cylindrical flasks or casings, made purposely in three sections lengthwise, the whole system of moulding extra-long hydraulic cylinders and rams, guns, etc., may be conveniently explained. Opportunities are here presented for a nice adjustment of the sections by such effective means as will insure a true vertical mould free of seams when all are closed together. Some very good practice may be introduced here; and along with many other schemes for obtaining the mould in these flasks, let a short plug be drawn through all the sections, together and separate, forming the head and socket, with loose pieces, or in any other way which the ingenuity of the instructor may suggest. This would, of course, be a dry-sand mould, and must have a loam-core struck on a barrel made for the occasion--a class of core-making too little practised outside of the pipe-foundries nowadays. This mould, when dried and closed, must be cast vertically.
Another way is to make a full pattern in halves, with a half core-box and sweep for striking off the upper side of core. In this case half-flasks should be used for moulding in green-sand and casting horizontally; the core to be formed in the aforesaid box on a full-length cast arbor in green-sand also. This will furnish excellent practice in another class of core-making too long neglected.
The same flasks must be fitted at the ends with parallels and bearings for carrying a centre spindle horizontally with which to sweep out each half of the mould in plastic material, exclusive of the pattern. The cores in this instance may be made in dry-sand halves and jointed, to vary the method somewhat. As this mould is prepared for drying, it may be cast alternately in a horizontal and vertical position, the latter method calling for some special arrangement for hoisting into a vertical position and lowering in the pit, as well as serving to illustrate the different modes of gating and securing the core.
Some suitable specimens of hollow ware should also be introduced into these schools. There are thousands of moulders who are to day as ignorant of the processes connected with this kind of moulding as were the Dutchmen who failed in making the first pot at Coalbrookdale in the year 1709. The flasks used for this purpose are ingenious and suggestive, and the very neat manipulations of the practised hollow-ware moulder are of a kind calculated to infuse new life into the somewhat slow and slipshod ways of the ordinary workman who attempts to make this particular class of work.
The eye and hand of the ambitious loam-moulder might receive training of a high order by assiduous practice on some object similar to a Y pipe, or any other analogous surface of ever-varying dimensions and constant change of curve--something possessing a surface impossible to form except by the hand, assisted by gauges and templates. Exercises of a similar kind may be given on green-sand surfaces by the use of forming-strips and sweeps, with a final smoothing over of the tools. These exercises need not necessarily be practised on dumb moulds; the more advanced could be taught to form surfaces corresponding to sketches given, such surfaces to receive the treatment necessary for the purpose of casting metal thereon.
The changes lately brought about by the introduction of a profuse display of fine-art work in modern buildings, most of which it is now desired to produce in cast iron, has created a demand for moulders with some experience in such work; and because these castings have hitherto been chiefly made in metals other than cast iron, it has been found difficult to supply this demand, for the simple reason that fine-art work in cast iron requires to be made in material to which the ordinary worker in bronze and other alloys is unaccustomed. There is no doubt that this demand will continue, and the subject should receive immediate attention in the technical schools, where special classes could be taught the entire process of statue- and figure-founding, including the cire-perdue and other modes of procedure connected with taking casts in metal and plaster, confining the study as near as possible to such classes of work as would be likely to find its way into our iron and brass foundries.
It will be very evident to those who are at all interested in foundry instruction at the technical schools that no institution of the kind should be without a modern moulding-machine of acknowledged merit. This is a comparatively new study, and is claiming the attention of founders more to-day than it has ever done in the past, simply because there has been a nearer approach made to hand-manipulation by the introduction of devices which have for their object the correct ramming of the moulds within the flasks. Some of these devices are automatic and trust-worthy, and the quantity as well as quality of work accomplished in a given time bears unmistakable evidence to the justice of their claims to universal recognition and adoption wherever large numbers of duplicate castings of a certain kind are in active demand. A good machine with stripping-plate attachment would be a valuable acquisition to the school; the minds of the students could be exercised in discovering methods for overcoming difficulties presented when the joining surfaces are irregular, and in framing schemes for automatically delivering such projections as are oblique to the general surfaces of the pattern. It is safe to say that no school of technology has been more successful than the Stevens Institute, from which place have been graduated a large number of engineers whose acknowledged ability has fully proved what can be done when competent instructors and judicious management are allowed full scope. Is it too much to ask that the moulder be allowed similar opportunities for distinguishing himself?