FLAX 



411 



These strips of wood are kept firm by cross iron holders B, secured by^iron bars c, 

 fastened to pieces of wood D, worked into the side walls of the tank, leaving a surface 

 four inches deep of water over the top of the flax. When the tank has been filled 

 with cold water through the wooden shoot E, the whole is rapidly heated to 78 

 Fahrenheit, by means of steam-pipes coiled under the false bottom. A second open 

 shoot F carries heated water at 90 to discharge on the surface, besides two closed 

 pipes o o, one of which brings hot water of the same temperature, and the other cold 

 water. When fermentation sets in, which is ordinarily in eight hours, the pipe, as 

 well as the shoot of water at 90, is set at play ; the first to create a continual current 

 of fresh water through the mass of flax, clearing off the products of decomposition, 

 and bringing them to the surface ; the second to drive this foul water to the openings 

 H H, where it is discharged by the overflow. The two pipes with heated and cold 

 water going to the bottom of the tank, as well as the two shoots containing cold and 

 hot water, to go to the surface, are also made use of to equalise the temperature during 

 the whole operation, which is ascertained by the use of a thermometer in the square 

 wooden box J J. The steeping of coarse straw requires 30 to 48 hours, medium 

 qualities 50 to 60 hours, and the finer descriptions 60 to 72 hours. The ' wet roll' 

 ing ' between cylinders after the steep is accompanied by a shower of water at 78, 

 not on the flax but on the top of the cylinders. This removes the remaining impu- 

 rities, and prepares the straw for being easily dried. The heated water may be ob- 

 tained from the waste water of a spinning-mill, or from a condensing steam-engine. 



919 



Ground Plan. 



Top of Tank. 



Side of Tank. 



Flax steeped by Schenck's system is dried in various ways. Some retters have 

 drying houses with heated air ; others set up the flax loosely on the root end, in the 

 field, or spread it thinly on the grass ; while others, again, clasp it between two slender 

 pieces of wood about a yard in length, and hang these up in a building open at the 

 sides, so that a current of atmospheric air is constantly passing through. 



In 1852 another mode of retting flax was introduced by Mr. Watt, of Glasgow. 

 Instead of immersing the stems in water, he subjected them to the action of steam. 

 Square iron chambers were employed, in which the flax-straw was packed. The door 

 by which it was introduced was then fastened by bolts or nuts, and steam was then 

 driven in. The steam penetrated the stems of the flax, and being partially condensed 

 on the top and sides of the iron chamber, a constant drip of water, lukewarm, fell upon 

 the flax. In twelve to fourteen hours the stems were removed, and, after being dried, 

 the fibre readily separated from the woody core, the water remaining in the iron 

 chamber being of a dark brown colour, without offensive odour. The fibre obtained by 

 this method was of a greyish colour, and was at first well thought of by manufacturers ; 

 but, in the end, on more extended trials it was found to possess several defects, and 

 Watt's system is not now carried out. 



