This tried and valuable improvement has been secured by Letters-Patent. These _Mills and Bolts_, or either of them separately are constantly being attached to old and new mills, warehouses and places where steam and water power can be had or used. We use on these Bolts Dufour & Co.’s celebrated Dutch Anchor brand of Bolting Cloth made up in best manner with 2½ inch strips of heavy ticking to come in contact with the ribs of reel. Some parties erroneously entertain the idea that a _portable mill_ is a temporary affair. They obtain this idea from the word _portable_. This word, applied to a mill, means only that the machinery is built in such a manner at the factory as to permit of its being shipped the same as any other machinery. Our portable mill has all the qualities for doing good work, and all the durability, that any old style mill has. It further has the advantage of enabling a man to put up his mill without near so much delay and expense as is required in the old style. In every instance where a portable mill has failed to do its work properly or to be durable, it has not been because it was a _portable_ mill, but because it was not constructed on _good well-tried_ principles, or of good material, or the fault may have been because it was not set up as it should be, or had not been properly managed after it was set up. Our Mills and Bolts are fitted up and put together ready to run, before shipment, then properly arranged for shipping, and delivered on board the cars at the proper depot here, and a through rate of freight contracted in the shipping receipt. COMPLETE PORTABLE GRINDING AND BOLTING FLOURING MILLS. The cuts, Figs. 1, 2, 3 and 4, are intended to show the different arrangements in buildings and are made by us of the following sizes of stones: 30, 36 and 42 inches diameter of upper-runners, and 26, 30 and 36 inch of the under-runner kind, with the bolts described fully elsewhere, of ample capacity and to meet the special demands of a custom mill, capable of making flour that will bear inspection in any market, at the same time good yields, and are as economical in the use of power as any mill in the United States. Drawings and directions to set up sent with each mill when ordered. It betters the arrangement to place the husk frame 20 inches below the floor; the discharge spout and hoppers all come at a convenient height for the miller to see into the hopper and operate the mill without stooping. In Figs. 1 and 3 they are shown thus. We advise making a platform in the rear of the mills over the belts. The stones and bolt-chest can be placed on same floor, as Fig. 1, or the bolt above as the situation requires. They will grind and bolt from six to fifteen bushels per hour according to size, and can be put in operation in a short time, and are no more liable to get out of repair than the best mill in use.