Grinding and Flouring, and Capacity.
All should know that the most important item in converting wheat into flour, is the Grinding Mill. Grain cannot be properly floured without burrs of good quality, dressed expressly for the purpose. Although a Miller of not much experience may sometimes make a pretty fair article of flour, yet those having the most experience will always find something to learn on this subject. It is best that the skill of an expert Miller be employed to prepare the face and furrows of the burrs and put them in order for grinding. Our mills, when properly dressed and in order, make a quality and yield of flour unsurpassed by any other mill, as the letters from our customers testify. Nevertheless, some of our mills, run and managed by unskillful hands, are making a tolerable article of flour, without much care to dress the burrs and keep in order, and sometimes are run a long time without any dressing. In grinding wheat, the burrs should be adjusted with precision, and should always occupy the attention of the Miller. In grinding grists, some damp and others dry, and of different qualities of wheat, the stones require close attention. The runner should be raised slightly for damp wheat; if not, the burrs are liable to heat the chop, and clog their grinding surfaces. If allowed to run too close on dry wheat, the bran will be cut and the flour made dark. These are common difficulties, but can be avoided by a careful miller who wants to make a fine article of merchantable flour, and good yield. The several qualities of wheat and its conditions, as well as the particular quality of flour required to meet the demand of any particular market, must be observed and understood in order to determine the best mode of grinding.
An Important Item.—Be sure to keep the furrows sufficiently deep, and especially so for corn, and see under heads of “Setting up and Starting” and “Keeping in Order.” Burrs are apt to throw out unground grain if run too slow, when, if the speed is increased, this difficulty is obviated.
Grinding Corn.—The dress is not that required for wheat. For corn, let every part of the surface be sharp, and the furrows cut deep; thus, with a high speed, the meal will not be heated. When the meal is ground hot, the stones are dull or the furrows not deep enough. It requires much more power to grind with dull stones or shallow furrows. Every stroke with a sharp pick makes a great number of sharp cutting edges upon French Burr, which cut easy, like a sharp tool in wood.
Be careful to keep the burrs well balanced and in tram. See observations elsewhere under this head.
In reference to the capacity of our mill we will give our opinions from the practical knowledge and experience we have had with them. Having a number of water and steam mills of our entire make and completion near our works and in our city, some having been built with special reference to having all first-class, our opportunities have been good near at hand for constant improvement. While much depends upon the power and condition of grain, our mills are made of the kind of burr stone, carefully selected, with furrows drafted and shaped in the most approved style, that the greatest attainable results may be accomplished. Under favorable circumstances our three feet mills have ground to make good flour and yields 14 bushels per hour, which, when in moderate condition as to sharpness, would do but 8 or 10 bushels. Our under-runner mills average a greater capacity than the upper-runner kind.
The amount our mills and mill stones will grind to do it well, is as great as that successfully obtained by any mill in existence, and always has been entirely satisfactory, oftentimes astonishing old and experienced millers. On one occasion two of our three feet upper-runner mills with two single reel bolts have made 100 bbls. of merchantable flour in 24 hours. With the larger sizes we could point to proportionally greater results.
Our three and three and a half feet mills are often found grinding faster than the four feet sizes of the old style of mills, at the same time doing as good and better work. These are facts, and the reasons why are simply because the stones are run at a greater speed, while the furrows are shaped to avoid heating, and properly drafted to distribute the grain evenly over the grinding surfaces. Also, much is owing to a good selection of the burr stock of which the stones are made. We conclude this subject by reference to some who have given us their views, carefully expressed in writing, and here published for the benefit of all those interested in milling.