When the water level in the TAIL RACE of a VERTICAL WATERWHEEL partly submerges the lower part of the wheel, it acts as a brake on its motion, greatly reducing the power available; this is known as being Backwatered. It can similarly impede the motion of a HORIZONTAL waterwheel.
(1) The process of adjusting the breaks and separations in a roller mill to produce the desired yield.
(2) Ensuring the post mill body is correctly balanced on the post.
(3) Ensuring the sails are correctly balanced to reduce the strain on the mill and increasing the ability to start in light winds.
(4).RUNNER STONE is balanced to run evenly.
(1) Large wooden barrel or cylinder containing blocks of hardwood. The barrel revolved on its axis, and was used to pulverise corned black powder and make mealed powder (q.v.).
(2) Large barrel or cylinder containing wooden or iron balls. The barrel is rotated on its axis to pulverise or polish the ingredients.
(1) the space between the sail bars of shuttered sails, usually containing three shutters.
(2) see MILL DAM.
(3) The division between the frames of a waterwheel.
(4) The space between roof couples in a house, mill or building.
Device generally assumed to have been invented in the middle of the seventeenth century in Holland and which superseded the older method of preparing the PULP by hammering or stamping the rags in a mortar. Also known as a HOLLANDER or a HOLLANDER BEATING MACHINE.
The cast iron plate which acts as the foundation for an item of machinery.
A flat plate of iron in the bottom of the trough in a STAMPER, against which the rags are pounded. In a HOLLANDER beater so that the PULP has to pass between it and the roll above it. The distance between the two determines the fibre length of the PULP.
A crank, triangular or L-shaped, pivoted at one apex and used for altering the direction of a mechanical force. Known as TRIANGLES if found on sails. Named from the use of this device in mechanical doorbells.
(1) A round iron or steel bar with a square (or later a hexagonal) head at one end and a screw thread at the other, to take a square (or later a hexagonal) internally-threaded nut. Used to hold or clamp two or more components together.
(2) A sliding wooden or metal bar or rod, used to secure a door, shutter or other device.
(3) The action of BOLTING. (to bolt).
A mechanical device for separating flour from bran, by beating it through a rotating cylinder of cloth. This was at first of wool, then calico & latterly of silk, hence the term 'silks', but other cloth may be used. First introduced in C16th (later SILK MACHINES were used).
A frame, usually six or eight sided, mounted on a SHAFT(1) and covered with a BOLTING CLOTH. As the frame revolves, the fine particles pass through the cloth & thus the flour is separated from the bran.
(1) A timber used to strengthen the rigidity of a mill frame, e.g. ties, triangulating beams.
(2) The diagonal support(s) of a smock or tower mill gallery.
(3) On tailpole winded tower or smock mill caps, the inner (or short brace) and outer (long brace) upright supports of the cap-mounted tail pole.
(1) Machine with two cracker rolls (q.v.) used to break slabs of mill-cake prior to pressing. Also termed cake-breaker.
(2) Gives the primary reduction of the pieces of rags to make them smaller and fit for their final beating in the Hollander. Also known as a BREAKER ENGINE.
(1) The main horizontal transverse beam supporting the NECK OF THE WINDSHAFT. Also known as WEATHER BEAM or RODE BALK.
(2)The transverse beam in the breast of the mill beneath the STONE FLOOR, in which case the BREAST BEAM is called the WEATHER BEAM. (East Anglia).
A WATERWHEEL which is turned by the weight of water in its BUCKETS, the water entering the buckets at about the level of the WHEELSHAFT. Developed in the 18th and 19th centuries See also HIGH BREAST WHEEL, LOW BREAST WHEEL.
An adjustable lever beam supporting the thrust bearing at the foot of the stone spindle & thus bears the weight of the runner stone; raised or lowered for adjusting or TENTERING the gap between the stones. Part of the hursting or hurst frame. Sometimes made of iron.
An open-topped iron box to contain and locate the FOOTBRASS of a vertical shaft. Usually has 3 or 4 BRIDGING SCREWS to locate and secure the footbrass to correctly align the shaft, and commonly fitted to BRIDGE TREES to carry the STONE SPINDLE. May also be fitted below the UPRIGHT SHAFT or other vertical shafts.
The screws set round a BRIDGING BOX which are used to adjust the position of the TOE BRASS to get the correct vertical alignment of a stone spindle or other vertical shaft. They usually have square heads, but may have ring-shaped heads similar to eye-bolts.
Truing up the spindle by adjusting the BRIDGING SCREWS or adjusting wedges to ensure the stone spindle is at right angles to the face of the BEDSTONE. The JACKSTAFF is used to indicate when the spindle is correctly adjusted. Also known as TRAMMING/TRAMMELING.
Partitions or receptacles around the rim of a WATERWHEEL in which the water is held, in order to use its weight to turn the wheel. In cases where a high velocity flow of water is directed into the buckets, some kinetic energy may be converted into useful energy by the wheel. Buckets are fitted to OVERSHOT, BACKSHOT and most BREAST-SHOT wheels. May vary in shape. See also SHROUDS, FLOATS, VENTILATED BUCKET and UNVENTILATED BUCKET.
also known as FRENCH BURR STONE. Imported millstones, usually built up of shaped blocks of freshwater quartz (siliceo calcareous stone) quarried in the Paris basin mainly near La Ferte sous Jouarre along the River Marne and at Epernon; set in cement or Plaster of Paris and bound with metal bands, for grinding wheat to produce flour. Introduced to England in the C15th. Generally about 4ft diameter and 1ft thick, weighing up to 18cwt. Very occasionally stones made from a single block of stone. Valued as the stone for producing white flour. Made up into millstones in numerous places in Britain.