Another very prominent feature of factory evolution is the increased use of labour-saving machinery. This practice has been in operation for a considerable time, but with marked acceleration during the last few years owing to the labour shortage occasioned by military service. This development of machine work has largely dispensed with that labour which involved any skill or training. The journeyman currier is now practically extinct. In the beam house, too, fleshing, unhairing and scudding are rapidly becoming machine instead of hand operations. Many devices are now being adopted also which reduce the quantity of unskilled labour needed. Instead of "handling" the goods from pit to pit, modern tanneries aim at moving the liquors. Thus in the "Forsare" and "Tilston" systems of liming, hides are placed in a pit and lie undisturbed until ready for depilation, the soak liquors and lime liquors being supplied and run off just as required, whilst these liquors are agitated as often as desired by means of a current of compressed air. This agitation replaces the "handling" up and down once practised. In the tanyard proper the same tendency is at work, "rockers" are increasingly preferred to "handlers," and an inversion of the press leach system permits the exhaustion of tan liquors by a gravity flow, and so avoids the handling forward from pit to pit. There is also a tendency to install lifts, overhead runways, trucks on lines, motor lorries, etc., to replace carrying, barrowing, carting, etc., and so to arrange the tannery that the minimum transport is needed. All these lines of evolution involve more intensive production, and necessitate much more careful supervision. It is not surprising, therefore, that the industry now feels that scientific oversight and administration are essential. A dozen years ago the trade chemists were largely unqualified men, whose work lay solely in the laboratory, and consisted mainly in the analysis of materials bought. To-day all large tanneries have qualified chemists, and it is realized that they are the practical tanners. Their function is so to control the manufacturing processes that all waste is avoided, and so to correlate and co-ordinate the manufacturing results with the analytical and experimental records of the laboratory, that constant improvements are made in the methods of production. The extended use of machinery, and the necessity for economy in coal and power, give the engineer also very large scope for useful work. Modern business conditions, moreover, have made necessary more skilful clerical work and accountancy in the large offices of a modern tannery.