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Sectional Elevations
1. MEASUSREMENTS(Back to top)
2. FLOORS(Back to top)
The design of joists, trusses, etc., to support the floors is, by modern standards, deplorable, and it is much worse at Fladbury than at Cropthorne Mill.
The only attempted triangulation at Fladbury Mill was in the roof trusses, but the important tension member that should go from wall to wall has been cut through to form doorways, in the
middle, in the grain store; in the same trusses, the strong rafters running through from wall plates to ridge pole do not go through in one piece, but the last three or four feet of rafter are missing, and a narrow piece of wood is inserted. In consequence part of the roof and all the third-floor load come down on the second-floor joists, which run from wall to wall.
Fladbury also was built badly on the second floor of the gable end nearest the weir, and facing Cropthorne Mill. Here the part of the grain store (area 25½ ft. x 14 ft.) was supported by one main joist, 13 in. x 10 in., down the centre of the 25½ ft. length. It makes the floor very weak indeed.
3. KING AND QUEEN TRUSSES (Back to top)
At Cropthorne Mill there are beautiful examples of one queen and three king post trusses. Each of these conform pretty closely to the U.S.A. bylaws. The English (Birmingham) bylaws make no mention of wood trusses, but in America, where much wood is used, detailed bylaws are given. But the arrangement of these four trusses is peculiar. The queen runs the long way of the mill about six feet away from the Lower Pound Wall, and the king trusses occupy the remainder of the space. One end is on the wall nearest the top-pound, while the other three ends rest on the queen truss-a poor design, because the load areas overlap one another. The designer at Cropthorne Mill understood the value of triangulation, but at Fladbury bad mistakes were made.
4. CORN-GRINDING SYSTEM (Back to top)
The process of grinding corn was exactly the same at both mills, so it will be sufficient to explain this at Cropthorne Mill only. The grain was stacked on the ground floor in sacks and was taken up to the third floor through trap-doors and holes in each floor. The ground floor of both mills was very liable to have a lot of flood water in it, i.e. maximum depth 4 ft. 4 in. at Cropthorne and 6 ft. 8 in. at Fladbury. By reference to the measurements given in Section 1 it will be noticed that the depth of water in the river had to rise 3 ft. at Cropthorne and only 8 in. at Fladbury before the ground floor was awash. This is therefore strong presumptive evidence that Mr. Sandys in 1636 raised the weir to a dangerous height for the storage of grain at Fladbury Mill; not, however, a serious disadvantage, for the power output from the two water-wheels was considerably increased.
The grain lift consists of a chain with a slip knot at the end, which is passed over one of the ears of the sack, the chain winding itself round a drum on the third floor. This drum is driven either by an open or a crossed belt. The belts are actuated by two ropes running the whole height of the mill; by pulling one rope, the be]t driving the drum shifts so as to lift the sack; by pulling the other rope, the bag descends. The ropes pass through each floor, and the two ropes, although no longer in existence, have left an interesting memorial behind them where two holes had been drilled through one of the 12 in. x 12 in. tension members of a king post truss. When you put your fingers up them they feel as smooth as glass-almost as if one of the ropes had been pulled through its hole only yesterday.
When the sacks have arrived at the third and top floor they are tipped into hoppers below the floor, each type of grain being kept separate. From their apex a small pipe, of about 2 in. diameter, runs down to the grinding stones, which revolve horizontally-the upper and nether mill stones.
The method of power transmission at the mills from the slow-running undershot water-wheel to the comparatively fast-running millstones requires the employment of skilled "millwrights," a word that is still used as a name for skilled mechanics who put shafting up and gearing. One comparatively straightforward way is to set up a fast-running shaft passing directly from the water-wheels on the ground floor. This necessitates one pair of bevel wheels at the bottom and another pair for each floor. The teeth of the bevel wheels were not made of cast iron but of very hard pieces of wood-hornbeam by preference-the framework of the bevel wheels themselves being of cast iron with rectangular holes on the bevel to receive the blocks of hornbeam. It was in fitting the blocks into the holes in the wheel that great skill was required of the millwright.
