MILLS, KILNS, MALT-HOUSES, ETC. 583 do. And ill case any alteration shall be directed by the said J. S., or liis surveyor, in the nature of the work, during progress, or any deviation shall be ordered by them from the foregoing particular and plans aforesaid, the same shall not vitiate or annul this agree- ment, but the difference shall be valued by J. P. of G., Surveyor, between the parties, and shall be added to or deducted from the amount of the present contract (as the case may be), and his decision shall be final. And further, if any or all of the said work should be performed in any way inferior to the description and intention of the particulars and drawings, or shall be deteriorated below a fair standard of good quality or sound work- manship, the same shall also be valued by the said J. P. as aforesaid, and deducted from the amount of the contract by the said J. S., and his decision in this case shall also be final. In witness whereof, I the undersigned have hereunto set my Contract, £22: 8s.: 8rf. hand, the day and year before written. T. O. 1 255. Remarks. The foregoing mill was built as an auxiliary to a larger one close adjoining it; and, to make it complete as a district mill, another, viz., a dressing-floor, would be required to be added. The floors required in a complete mill are, the ground floor, the stone floor, the di-essing-floor, the bin floor, and the stage floor in the roof. Design II. — The Construction of a Building for containing the Machinery and Apart~ merits belonging to a Vertical JFitidmill, with Remarks on the different Kinds of fi'lndmills. 1256. JFindmills are supposed to have been brought into France from the East in the sixth century. They are of two kinds, the vertical and horizontal j but the latter are rarelj-, if ever, used for commercial purposes, though they might sometimes be employed in gentlemen's grounds for raising water to supply the house, and other purposes, where the sails of the vertical windmill would be considered so unsightly as to render its erection inadmissible. 1257. The Vertical Windmill is the kind in most common use, and consists of an axis or wind-shaft, placed in the direction of the wind, and usually inclining a little upwards from the horizontal line. At one end of this, four long arms or yards are fixed per- pendicularly to the axis, crossing each other at right angles ; into these arms small cross bars are mortised at right angles, and other long bars are joined to them which are parallel to the length of the arms, so that the bars intersect each other in the manner of latticework ; and form a surface on which a cloth can be spread to receive the action of the wind. These are called sails : they are in the form of a trapezium, and are usually nine yards long and two yards wide. The circular motion is produced by the obliquity of the planes of these surfaces from the plane in which all the four arms are situated. By these means, when the wind blows in the direction of the axis, it does not impinge upon the sails at right angles to the surfaces, but strikes obliquely : hence the effort of the sail to recede from the wind causes it to turn round the common axis, and the four sails are all made oblique in the same direction, so as to unite their efforts for the common object. For the wind to act with the greatest efficiency upon the sails, it is requisite for the wind-shaft to have the same direction as the ■wind ; but as this direction is constantly changing, some apparatus is necessary for bringing the wind-shaft and sails into the proper position. This is done by turning the axis of the sails round in a horizontal direction. There are two methods of effecting this. 1258. In the oldest windmills, the whole of the building which contains the machinery is sustained upon a vertical post firmly fixed as a stand or foot, upon which the whole of the machine can be turned by a lever so as to present the sails to any quarter of the horizon whence the wind blows ; and hence these are called post windmills, and are neces- sarily made of wood. They are of small size, and can only contain one pair of stones. The mill-house is of a rectangular form, but narrow in the direction which is presented to the wind. It is two stories high, the main shaft and millstones being in the upper chamber, while the lower is only used to contain sacks of flour, and to receive the post on which the mill turns round horizontally to face the wind. The whole building is turned by means of a lever, that also serves for a step-ladder into the upper chamber ; and when it is wished to prevent the mill from turning, it is fastened to the posts by a cord. There is also a small windlass to assist in moving the miU round. These windmills are generally used for grinding corn or expressing oils ; being unfit for other purposes, on account of there being so little room for machinery. 1 259. 27(6 other kind nf vertical windmill is called a smock, or tower, windmill, in which only the dome cap or head, which contains the axis of the sails, and covers the great cog- wheel, turns round horizontally ; the other parts of the machinery being contained in a fixed building, which rises up in the form of a conical tower, and is composed of masonry, brick or timber framing ; lieing surmounted by this movable cap or dome, which is sup- ported on rollers, so as to turn round easily. 1260. TheSmock, or Tower, Mills are considered the best, because the building which ccn-
