Crude as these means were they were the chief ones used in milling until within a century and a quarter ago.

In a very recent bright work published in London, by Richard Bennett and John Elton, on Corn Mills, etc., they say on this point: "The mill of the last century, that, by which, despite its imperfections, the production of flour rose from one of the smallest to one of the greatest and most valuable industries of the world, was essentially a structure of few parts, whether driven by water or wind, and its processes were exceedingly simple. The wheat was cleaned by a rude machine consisting of a couple of cylinders and screens, and an air blast passed through a pair of mill-stones, running very close together, in order that the greatest amount of flour might be produced at one grinding. The meal was then bolted, and the tailings, consisting of bran, middlings and adherent flour, again sifted and re-ground. It seems probable that the miller of the time had a fair notion of the high grade of flour ground from middlings, but no systematic method of procedure for its production was adopted."

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The upper and the nether mill-stone is still a most useful device. The dress," which consists of the grooves which are formed in the meeting faces of the stones, has been changed in many ways to meet the requirements in producing flour in varying degrees of fineness. Machines have been invented to make such grooves. A Swiss machine for this purpose consists of two disks carrying diamonds in their peripheries, which, being put in rapid revolution, cut parallel grooves in the face of the stone.

A great advance in milling was made both in America and Europe by the inventions of Oliver

Evans. Evans was born in the State of Delaware, U.S., in 1755, and died in 1819. He was a poor boy and an apprentice to a wheelwright, and while thus engaged his inventive powers were developed. He had an idea of a land carriage propelled without animal power. At the age of 22 he invented a machine for making card teeth, which superseded the old method of making them by hand. Later he invented steam-engines and steam-boats, to which attention will hereafter be called. Entering into business with his brothers within the period extending from 1785 to 1800, he produced those inventions in milling which by the opening of the 19th century had revolutionised the art. A description of the most important of these inventions was published by him in 1795 in a book entitled The Young Millwright and Miller's Grist. Patents were granted Evans by the States of Delaware, Maryland and Pennsylvania in 1787, and by the U.S. Government in 1790 and 1808.

As these inventions formed the basis of the most important subsequent devices of the century, a brief statement of his system is proper:

From the time the grain was emptied from the waggon to the final production of the finest flour at the close of the process, all manual labour was dispensed with. The grain was first emptied into a box hung on a scale beam where it was weighed, then run into an elevator which raised it to a chamber over cleaning machines through which it was passed, and reclaimed by the same means if desired; then it was run down into a chamber over the hoppers of the mill-stones; when ground it fell from the mill-stones into conveyors and as carried along subjected to the heated air of a kiln drier; then carried into a meal

elevator to be raised and dropped on to a cooling floor where it was met by what is called a hopper boy, consisting of a central round upright shaft revolving on a pivot, and provided with horizontal arms and sweeps adapted to be raised and lowered and turned, by which means the meal was continually stirred around, lifted and turned on the floor and then gathered on to the bolting hoppers, the bolts being cylindrical sieves of varying degrees of fineness to separate the flour from its coarser impurities, and when not bolted sufficiently, carried by a conveyor called a drill to an elevator to be dumped again into the bolting hoppers and be re-bolted. When not sufficiently ground the same drill was used to carry the meal to the grind stones. It was the design of the process to keep the meal in constant motion from first to last so as to thoroughly dry and cool it, to heat it further in the meantime, and to run the machines so slowly as to prevent the rise and waste of the flour in the form of dust.

The Evans system, with minor modifications and improvements, was the prevailing one for three-quarters of a century. New mills, when erected, were provided with this system, and many mills in their quiet retreats everywhere awoke from their drowsy methods and were equipped with the new one.

But the whole system of milling has undergone another great change within the last thirty years:

During that time it has been learned that the coarser portion or kernel of wheat which lies next to the skin of the berry and between the skin and the heart is the most valuable and nutritious part, as it consists largely of gluten, while the interior consists of starch, which when dry becomes a pearly powder. Under the old systems this coarser part,

known as middlings, was eliminated, and ground for feed for cattle, or into what was regarded as an inferior grade of flour from which to make coarse bread. It was customary, therefore, under the old method to set the grinding surfaces very close with keen sharp burrs, so that this coarser part was cut off and mixed with the small particles of bran, fine fuzz and other foreign substances, which was separated from the finer part of the kernel by the bolting.

The new process consists of removing the outer skin and adherent impurities from the middlings, then separating the middlings from the central finer part and then regrinding the middlings into flour.

This middlings flour being superior, as stated, to what was called straight grade, it became desirable to obtain as much middlings as possible, and to this end it was necessary to set the grinding surfaces further apart so as to grind high, hence the high milling process as distinguished from low milling. For the better performance of the high rolling process, roller mills were invented. It was found that the cracking process by which the kernel could be cracked and the gluten middlings separated from the starchy heart could best be had by the employment of rollers or cylinders in place of face stones, and at the same time the heating of the product, which injures it, be avoided.

The rollers operate in sets, and successive crackings are obtained by passing and repassing, if necessary, the grain through these rollers, set at different distances apart. The operation on grains of different qualities, whether hard or soft, or containing more or less of the gluten middlings, or starchy parts,

and their minute and graded separation, thus are obtained with the greatest nicety.

The Hungarians, the Germans, the Austrians, the Swiss, the English and the Americans have all invented useful forms of these rollers.

This process was accompanied by the invention of new forms of middlings separators and purifiers, in which upward drafts of air are made to pass up through flat, graded shaking bolts, in an enclosed case, by which the bran specks and fuzz are lifted and conveyed away from the shaken material. In some countries, such as the great wheat state of Minnesota, U.S., where the wheat had before been of inferior market value owing to the poorer grade of flour obtained by the old processes, that same wheat was made to produce the most superior flour under the new processes, thus increasing the yearly value of the crops by many millions of dollars.

Disastrous flour dust explosions in some of the great mills at Minneapolis, in 1877-78, developed the invention of dust collectors, by which the suspended particles of flour dust are withdrawn from the machinery and the mill, and the air is cleared for respiration and for the production of the finest flour, while the mill is kept closed and comfortable in cold seasons. One of the latest forms of such a collector has for its essential principle the vertical or rotatory air current, which it is claimed moves and precipitates the finest particles.

The inventions in the class of mills have so multiplied in these latter days, that nearly every known article that needs to be cleaned and hulled, or ground, or cracked or pulverized, has its own specially de signed machine. Wind and water as motive powers have been supplanted by steam and electricity. It