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The purpose of this paper is to evaluate the tool experiences using torque during welding as a means of in-process sensing for tool wear. Metal matrix composites (MMCs) are materials with immense potential for aerospace structural applications. The major barrier to implementation of these materials is manufacturability, specifically joining MMCs to themselves or other materials using fusion welding. Friction stir welding (FSW) is an excellent candidate process for joining MMCs, as it occurs below the melting point of the material, thus precluding the formation of degradative intermetallics’ phases present in fusion welded joints. The limiting factor for use of FSW in this application is wear of the tool. The abrasive particles which give MMCs their enhanced properties progressively erode the tool features that facilitate vertical mixing and consolidation of material during welding, resulting in joints with porosity. While wear can be mitigated by careful selection of process parameters and/or the use of harder tool materials, these approaches have significant complexities and limitations.

This study evaluates using the torque the tool experiences during welding as a means of in-process sensing for tool wear. Process signals were collected during linear FSW of Al 359/SiC/20p and correlated with wear of the tool probe. The results of these experiments demonstrate that there is a correlation between torque and wear, and the torque process signal can potentially be exploited to monitor and control tool wear during welding.

Radial deterioration of the probe during joining of MMCs by FSW corresponds to a decrease in the torque experienced by the tool. Experimentally observed relationship between torque and wear opens the door to the development of in-process sensing, as the decay in the torque signal can be correlated to the amount of volume lost by the probe. The decay function for tool wear in FSW of a particular MMC can be determined experimentally using the methodology presented here. The decay of the torque signal as the tool loses volume presents a potential method for control of the wear process.

This work has near-term commercial applications, as a means of monitoring and controlling wear in process could serve to grow commercial use of MMCs and expand the design space for these materials beyond net or near-net-shape parts.

The forces and torques associated with friction stir welding (FSW) are discussed as they relate to implementation of the welding process with industrial robots. Experimental results are presented that support the conclusions drawn from models developed by others. It is shown that even with heavy‐duty industrial robots with high stiffness, force feedback is important for successful robotic FSW. Methods of implementing force feedback are reviewed. Attention is paid to stability issues that arise with variations in tool rotation and travel speed. Successful implementations of robotic FSW are cited.

If additional evidence were needed of the connection between food supply and the spread of infectious disease, it would be found in a report recently presented to the Finsbury Borough Council by its Medical Officer of Health, Dr. GEORGE NEWMAN. It appears that in the early part of May a number of cases of scarlet fever were notified to Dr. NEWMAN, and upon inquiry being made it was ascertained that nearly the whole of these cases had partaken of milk from a particular dairy. A most pains‐taking investigation was at once instituted, and the source of the supply was traced to a farm in the Midlands, where two or three persons were found recovering from scarlet fever. The wholesale man in London, to whom the milk was consigned, at first denied that any of this particular supply had been sent to shops in the Finsbury district, but it was eventually discovered that one, or possibly two, churns had been delivered one morning, with the result that a number of persons contracted the disease. One of the most interesting points in Dr. NEWMAN'S report is that three of these cases, occurring in one family, received milk from a person who was not a customer of the wholesale dealer mentioned above. It transpired on the examination of this last retailer's servants that on the particular morning on which the infected churn of milk had been sent into Finsbury, one of them, running short, had borrowed a quart from another milkman, and had immediately delivered it at the house in which these three cases subsequently developed. The quantity he happened to borrow was a portion of the contents of the infected churn.

In a Report, issued on July 9, 1896, the Select Committee on Food Products Adulteration recommended the establishment of a central government scientific authority, who should act as a court of reference upon scientific questions arising under the Adulteration Acts, and who should be empowered, at their discretion, to prescribe standards and limits as to the quality and purity of food. It was rightly held by the Select Committee that the constitution of such an authority is an absolute necessity in order that the all‐important question of food standards may be duly considered and dealt with, and that all matters affecting the administration of the Acts and involving scientific considerations may be placed on a more satisfactory footing. The Committee also expressed the opinion that the formation of such an authority would result in the removal of many practical difficulties met with in the administration of the Acts, and would largely obviate the costly litigation in which public bodies, traders, and others are constantly liable to be involved under existing conditions. Nothing whatever has been done to give effect to the recommendation of the Committee in spite of the fact that the necessity for some such course of action as that indicated has been demonstrated beyond possibility of question, and that further evidence proving the wisdom of the Committee's suggestion is constantly afforded. The Islington brandy case provides the latest illustration of the extremely unsatisfactory conditions under which public bodies are required to administer the Acts and under which traders have to answer charges made against them. A local grocer was summoned by the Islington Borough Council for selling, as brandy, a liquid which was certified by the Public Analyst to contain 60 per cent. of spirit not derived from the grape, and which was therefore not of the nature, substance and quality of the article demanded. The vendor naturally referred the matter to the firm who had supplied him. The case was taken up by a traders' association, and, after five lengthy hearings, in the course of which much expert evidence was given on both sides, resulted in a conviction and the infliction of a penalty of £5 and £50 costs—an amount which probably represents only a fraction of the expense involved. For the present we do not propose to review the scientific evidence which was put forward by the prosecution and by the defence. There is no doubt that Mr. FORDHAM, the magistrate who heard the case, was perfectly right in taking the view that the term “brandy,” when unqualified, means a spirit distilled from wine or from fermented products of the grape. It is also perfectly plain that when a person asks for brandy and is supplied with coloured grain spirit, or with a mixture of grain spirit and true brandy, he is prejudiced, and that the vendor commits an offence under the Acts. The fact that the term “brandy” has been commonly applied to “silent spirit” coloured and flavoured to imitate true brandy, or to mixtures of brandy and alcohol derived from other sources than the produce of the grape, is not a legitimate excuse for the sale of such factitious articles as “brandy.” The great difficulty lies in differentiating by analytical means between the genuine article and the imitation. The vast majority of people, being utterly ignorant even of the elements of chemistry, labour under the impression that all that need be done in a matter of this kind is to tell the Public Analyst to “analyse,” and that full, exact, and absolutely definite information which nobody can call in question, will be forthcoming as a matter of course. The evidence given in the case under consideration is quite enough in itself to show the absurdity of this assumption. On the one hand the Public Analyst stated that he was satisfied, from the results of his general investigations in regard to brandy and from the results of his analysis of the sample submitted to him, that this sample contained 60 per cent. of spirit other than that derived from the produce of the grape. On the other hand, a number of analytical experts called for the defence asserted that in the present state of analytical knowledge it was perfectly impossible for any Public Analyst to arrive at the conclusion mentioned in regard to the sample in question, and that, as a fact, the analytical evidence adduced did not justify the statement made in the certificate on which the proceedings were founded. The defence do not appear to have denied that the Public Analyst might be right. In reality it appears only to have been contended that his analytical evidence was not, sufficient to prove that he was so. At any rate the experts called for the defence certainly did not prove by scientific evidence that he was wrong.

In a volume of the Cornhill Magazine published in the year 1860 we have discovered an article entitled “Adulteration and its Remedy” which well deserves the attention of those persons who imagine that we have made “wonderful progress” during the past half century and that the trade morality of to‐day is infinitely superior to the trade morality of the past. The unknown author of this article must have had a very clear appreciation of the nature of the gigantic evil upon which he wrote and of the character and probable effectiveness of the remedies to be applied. The adulteration of the period is described by him as a “strange, disgusting and poisonous demon” and while it is true that at the time, as shown by the revelations of the “Lancet Sanitary Commission,” there existed many forms of gross, disgusting and poisonous adulteration which are but rarely detected nowadays, our author's somewhat hyperbolic definition may still be regarded as applicable. For many of the grosser forms of adulteration prevalent fifty years ago were largely due to the ignorance of the adulterator. His prototype of the present day is no more troubled with moral scruples than he was. The dissemination and absorption of knowledge has not been accompanied, as some rabid “educationalists’ would have us believe, by any improvements in morality and virtue. The “faker ” of to‐day is merely a more skilful “faker” than his predecessor. He knows the value and makes full use of “expert” assistance, both scientific and legal, for the purpose of facilitating his escape—easy enough in any case—from what grip there is in that cranky and lumbering legislative machinery which is innocently supposed by the majority of people in this country to act as a sufficiently effective deterrent and repressant.

Month after month we bring forward additional evidence of the injury resulting from the use of chemical “preservatives” in food, while the Authorities feebly hesitate to give specific legal effect to the recommendations of the Departmental Committee which made such a complete inquiry into this question. The evidence upon which those recommendations were based has been fully corroborated by a number of different observers. FERE and others have shown that, as regards boric acid and borax, even when administered in the smallest medicinal doses, there is always the risk that these drugs may aggravate, or even produce, renal diseases. These observations have been confirmed by the work of Dr. CHARLES HARRINGTON, an account of which has been recently published. Twelve cats were fed on the same food; six were treated with borax, one had no preservative, and five were given a preservative which had no apparent effect. The experiment extended over a period of 133 days, the quantity of borax given averaging about 0.5 grms, per diem. Three of the borated cats soon became ill, and one died at the end of six weeks. On the termination of the experiment the cats were all killed, and upon examination it was found that the organs of the six cats which had not taken borax were in perfectly sound and healthy condition, while the others, with one exception, were all suffering from nephritis. Of course, instances are recorded in which patients have been treated with borax and boracic acid with apparently no injurious result, but as a general rule these experiments have been of too short duration to allow of the desired information being arrived at, and the results must therefore be regarded as inconclusive and unreliable. It is perfectly evident that the kidneys may be for a short time quite capable of eliminating many objectionable substances, but the long‐continued use of such bodies, as Dr. HARRINGTON'S researches clearly indicate, sets up an inflammatory condition of the kidneys which, of course, interferes with the effective performance of their proper functions, and lays the foundations for complications of the most serious nature.

At a recent inquest upon the body of a woman who was alleged to have died as the result of taking certain drugs for an improper purpose, one of the witnesses described himself as “an analyst and manufacturing chemist,” but when asked by the coroner what qualifications he had, he replied : “I have no qualifications whatever. What I know I learned from my father, who was a well‐known ‘F.C.S.’” Comment on the “F.C.S.” is needless.

Sane and civilised people, capable of thinking clearly, now recognise that if the peace of the world is to be secured, and that if another and even greater cataclysm is to be prevented, the Huns and their accomplices must be crushed, and crushed so completely that their recovery of the power to do evil shall be rendered utterly impossible. The persons who are “Pro‐German” for reasons at present best known to themselves, and the peace‐at‐any‐price cranks, may be left out of consideration except in so far as the advisability of placing the former under lock and key and the latter in lunatic asylums demands attention. A premature and inconclusive peace which would make it possible for our abominable enemies to rise again and threaten civilised mankind is unthinkable, and the Allied Powers must of necessity carry on the war until the Thugs of Europe have bitten the dust and have been compelled to sue for peace without terms or conditions. When the “Central Powers” have been forced to their knees, and the Allied armies of occupation have made them taste the bitterness and humiliation of invasion, the surviving criminals will be placed at the bar to receive the sentence of their judges, while the populations who have approved and applauded their hideous acts must also have adequate punishment meted out to them. What form is that punishment to take? The long and ghastly account has got to be read out and settled—so far as it can be settled in this world. What is to be the settlement?

As yet there are no indications that the President of the Local Government Board intends to give the force of law to the recommendations submitted to him by the Departmental Committee appointed by the Board to inquire into the use of preservatives and colouring matters in food. It is earnestly to be hoped that at least some of the recommendations of the Committee will become law. It is in the highest degree objectionable that when a Committee of the kind has been appointed, and has carried out a long and difficult investigation, the recommendations which it finally makes should be treated with indifference and should not be acted upon. If effect should not be given to the views arrived at after the careful consideration given to the whole subject by the Committee, a very heavy responsibility would rest upon the Authorities, and it cannot but be admitted that the Committee ought never to have been appointed if it was not originally intended that its recommendations should be made legally effective. Every sensible person who takes the trouble to study the evidence and the report must come to the conclusion that the enforcement of the recommendations is urgently required upon health considerations alone, and must see that a long‐suffering public is entitled to receive rather more protection than the existing legal enactments can afford. To refrain from legalising the principal recommendations in the face of such evidence and of such a report would almost amount to criminal negligence and folly. We are well aware that the subject is not one that is easily “understanded of the people,” and that the complicated ignorance of various noisy persons who imagine that they have a right to hold opinions upon it is one of the stumbling blocks in the way of reform; but we believe that this ignorance is confined, in the main, to irresponsible individuals, and that the Government Authorities concerned are not going to provide the public with a painful exhibition of incapacity and inaction in connection with the matter. There is some satisfaction in knowing that although the recommendations have not yet passed into law, they can be used with powerful effect in any prosecutions for the offence of food‐drugging which the more enlightened Local Authorities may be willing to institute, since it can no longer be alleged that the question of preservatives is still “under the consideration” of the Departmental Committee, and since it cannot be contended that the recommendations made leave any room for doubt as to the Committee's conclusions.

The institution of food and cookery exhibitions and the dissemination of practical knowledge with respect to cookery by means of lectures and demonstrations are excellent things in their way. But while it is important that better and more scientific attention should be generally given to the preparation of food for the table, it must be admitted to be at least equally important to insure that the food before it comes into the hands of the expert cook shall be free from adulteration, and as far as possible from impurity,—that it should be, in fact, of the quality expected. Protection up to a certain point and in certain directions is afforded to the consumer by penal enactments, and hitherto the general public have been disposed to believe that those enactments are in their nature and in their application such as to guarantee a fairly general supply of articles of tolerable quality. The adulteration laws, however, while absolutely necessary for the purpose of holding many forms of fraud in check, and particularly for keeping them within certain bounds, cannot afford any guarantees of superior, or even of good, quality. Except in rare instances, even those who control the supply of articles of food to large public and private establishments fail to take steps to assure themselves that the nature and quality of the goods supplied to them are what they are represented to be. The sophisticator and adulterator are always with us. The temptations to undersell and to misrepresent seem to be so strong that firms and individuals from whom far better things might reasonably be expected fall away from the right path with deplorable facility, and seek to save themselves, should they by chance be brought to book, by forms of quibbling and wriggling which are in themselves sufficient to show the moral rottenness which can be brought about by an insatiable lust for gain. There is, unfortunately, cheating to be met with at every turn, and it behoves at least those who control the purchase and the cooking of food on the large scale to do what they can to insure the supply to them of articles which have not been tampered with, and which are in all respects of proper quality, both by insisting on being furnished with sufficiently authoritative guarantees by the vendors, and by themselves causing the application of reasonably frequent scientific checks upon the quality of the goods.