117 CHAPTER II. ON CORN MILLS. IN the first part of this work was sketched a very brief notice of the antiquity of corn mills, and the state in which grinding went on from generation to generation, until it came down with comparatively little improvement to the present time. During the Jewish period, Moses speaks of the nether and upper millstones, and for a succession of ages in Egypt, Greece, and Rome, the quern and some other description of mills, driven by horses or by bullocks, appear to have been in use without change or improvement of any kind. The same may be said of the Middle Ages, which were anything but fruitful of improvement or mechanical invention; and, until the close of the last century, little or no progress was made in the process of grinding, or the development of those principles by which the whole operation is reduced to a system. Corn mills, like every other description of milling, have of late years undergone great changes, and the introduction of steam has given certainty and effect to the mill operations of every description of manufacture, that was inconceivable at a previous epoch. The fact of having motive power at command in every district of the country, mills being no longer dependent upon the state of the wind or the supply of water, has now as nearly as possible supplanted the old wind and water contrivances, and transferred the operation of grinding, with all its necessary improvements, into the very heart of towns. From this certainty of action we derive most of the changes and improvements that are now visible in corn mills, and in every other description of manufacture throughout the country; we have therefore now to show in what these improvements consist, and how they may be maintained upon sounder principles than those known to our forefathers. The corn mills chosen for illustration are, one of three pairs of stones erected at Constantinople for the Seraskier Halil Pasha. in 1842, and the other of thirty pairs of stones for a Russian company at Taganrog, on the borders of the Black Sea. The first was built under conditions that the building should be entirely of iron, that it might not be burnt to the ground by the fires which so frequently occur in the Turkish capital. The other was intended for the purpose of grinding the large supplies of wheat which are grown on the steppes of Southern Russia for the European markets, and also for the supply of bread and biscuits for the Russian navy. It is now upwards of forty years since the new system of corn mills, having the millstones in a continuous line, was first adopted. For many years it was called in question, and it met with a determined opposition from the old millers and millwrights, who stoutly maintained that the bevel-wheel principle was decidedly inferior to the old plan of stones ranged round a large spur wheel. Time, however, showed the advantages of the new plan, as it not only proved that the bevel wheels worked as well as the spur, but it gave greatly increased facilities for the operations of the mill in the different processes of cleansing, grinding, dressing, sacking, &c., of the flour, as it came from the machine ready for the baker. A description of this mill, and of the Old Union Mills, Birmingham, was published some years since by Messrs. Blackie and Son, in their work, entitled 'The Engineers' and Mechanics' Assistant,' and, as that work contains an accurate description of this system of mills, I have extracted from it large quotations, accompanied with improvements, which have since been introduced. Fig. 252 is a sectional elevation of the mill, the line of section being taken in a longitudinal direction, and exhibiting the position of the stones, the engine, and driving gearing, and of such portions of the subordinate apparatus as are visible on the side of the mill which is exposed to view. It also exhibits the millstones P P P, sections of the ele vator v v', screw creepers r'r', and the wheat bins or hoppers In these will be seen the driving gear K K, first motion wheels K L N N, and vertical shaft c'c', by which motion is transmitted to the machinery in the floors above. Fig. 253 is a plan of the bottom floor, showing the engine F and boilers & G, corresponding to the above, and taken on a horizontal line passing through the lower story of the mill. Fig. 254 is a transverse section of the entire mill, in which are shown the garners for undressed and dressed wheat Q Q, the mechanism by which it is cleaned and conveyed from the former into the latter, as described in the text, page 124, and in the references at pages 125 and 126; the sack teagle, &c., as shown at H'D, &c. P G Fig. 255 is a plan of the first floor, corresponding with the plan, fig. 253, the line of section being taken through the first story of the mill. The house in which this mill is contained consists of an assemblage of plates of sheet iron A, A, A, of a suitable thickness, consolidated and bound together by the square cast-iron columns, or pilasters B, B, B, and by the strong cast-iron girders C, C, C, situated at such a height as to oppose and neutralise the strain of the principal working parts. It is surmounted by an arched roof D,D, formed of plates of corrugated sheet-iron. A wall of masonry E, E is erected in the interior, for the purpose of affording a foundation for the bearings of the heavier gearing of the mill. The motive power is supplied by a high-pressure steam-engine F, of 12 horse |