510 FULLING 



Trembley's engine, tried in 1840, and adopted for a boat which ran regularly between 

 Marseilles and Algiers, was worked with steam and the vapour of ether. Sulphuric 

 other boils at a temperature of 37 Cent. ; condensed steam preserves sufficient heat 

 to convert ether into vapour which, by its expansion, adds a certain amount of 

 power to that already produced. This experiment, however, was not successful, and 

 the engines constructed upon this system were considered extremely dangerous. The 

 substitution of chloroform for ether, proposed by M. Lafond, of the French Navy, was 

 not more satisfactory. 



Capt. Ericson, in his engine, which was remarkable from a theoretical point of view, 

 constructed about 1852, appears to have been the first inventor who succeeded in 

 utilising atmospheric air in thermic engines. But although his apparatus has been 

 employed in America, under various circumstances, and especially for vessels, the hot- 

 air engine, whether on the system of Ericson, Franchot, Lemoine (of Rouen), Belou or 

 others, has not yielded really practical results or rendered any real service. It is well 

 known that the effects of hot-air engines should far exceed those of good steam- 

 engines. Our best motors .actually consume, as already stated, a kilogramme of coal 

 per horse per hour; if we admit that the heating apparatus of a hot-air engine 

 transmits two-thirds of the heat developed in the furnace, that the mechanism utilises 

 60 per cent, of the possible mechanical power, and that the coal produces only 7,500 

 imits of heat ; lastly, if wo estimate the absolute theoretical effect at - 50, the con- 

 sumption of a hot-air engine will, under these circumstances, be equal to 0'424 per 

 horse per hour a very reduced amount. It would be to despair of human ingenuity 

 not to believe that such a result will some day be obtained. See AIR ENGINE. 



FUXiGURATXOXr designates the sudden brightening of the melted gold and silver 

 in the cupel of the assayer, when the last film of vitreous lead and copper leaves their 

 surface. 



FULLER'S EARTH. ( Terre a foulon, Argile smectiquc, Fr. ; Walkcrerde, Ger.) 

 In geology this term is applied to the clayey deposit which intervenes between the 

 calcareous strata commonly known as the Bath or Great Oolite, and the Inferior 

 Oolite. A sandy argillaceous earth is met with in the upper part of the clay in 

 question, to which the name Fuller's earth was given from its adaptability for fulling 

 or cleansing cloth, when first woven, from grease or other impurities. The term 

 thus limited originally to a particular stratum was subsequently applied to the entire 

 formation by Dr. "William Smith in his classification of the British strata, and 

 has ever since retained its place in geological nomenclature. The fuller's earth 

 above mentioned was formerly procured in considerable quantities from the Downs, 

 to the south of Bath, whence it was sent to the cloth factories of Gloucestershire. 

 Of late years, however, an artificial substitute has been found in a chemical prepa- 

 ration, and the demand for the natural production has decreased so far, that little or 

 none of it is now procured in the West of England. The fuller's earth of Reigate is 

 found in strata of a much more recent date than those alluded to above, and forms a 

 part of the Lower Greensand. See GREENSAND. 



From Reigato 12,000 tons of dried fuller's earth are raised annually. There are 

 two varieties, called the blue and yellow ; their analyses are respectively 



Blue Yellow 



Alumina ...... 18 11 



Silica .42 44 



Lime 4 5 



Magnesia 2 2 



Oxide of Iron 6 10 



Soda 5 5 



The other places from which fuller's earth has been obtained, are Penenden 

 Heath, Maidstone, Fromc, Lonsdale, Coombe Hay, English Coombo, and Duncorn Hill 

 in Gloucestershire, and at one locality in Bedfordshire. H. W. B. 



FUXiXiERS' TEAZEL. Dipsacus (5tya, thirst}, so called because the bases of 

 the leaves are, in many species, connate, so that they enclose a ravity which con- 

 tains water ready to allay thirst. The fullers' tcazul is the Dipsacus fullonum; 

 the bracts of the head arc very spiny, and are much used for carding cloth; con- 

 sequently the teazel is cultivated in many parts. Many Carding machines have l>ei-n 

 introduced, but the best cloth weavers still pn-fi-r tin- tr.i/d for finishing their cloth. 



FUXiXiXXTG. The art of cle.msinir, M'ourinir. and j-rcssing woollen manufactures. 

 The object is to render them stronger and firmer. It is called also mill hi,/, 1 

 the cloths are scoured by a water mill. 



The principal parts of a fulling mill are the wheel with its trundle, which 

 motion to the tree or spindle whose teeth communicate that motion to the staiujxi 1 .- 

 or beaters, which fall into troughs, wherein the cloth is put, with the fuller's earth. 



