TURKEY RED 1045 



velocity of the entering water, and thus there is no impact between the water and the 

 wheel ; but, on the contrary, the water enters the radiating conduits of the wheel gently, 

 that is to say. with scarcely any motion in relation to their mouths. In order to 

 attain the equalisation of these velocities, it is necessary that the circumference of the 

 wheel should move with the velocity which a heavy body would attain in falling 

 through a vertical space equal to half the vertical fall of the water, or, in other 

 words, with the velocity due to half the fall ; and that the orifices through which the 

 water is injected into the wheel-chamber should be conjointly of such an area, that, 

 when all the water required is flowing through them, it also may have the velocity due 

 to half the fall. 



Thus one half only of the fall is employed in producing velocity in the water ; and, 

 therefore, the other half still remains, acting on the water within the wheel-chamber 

 at the circumference of the wheel, in the condition of fluid pressure. Now, with the 

 velocity already assigned to the wheel, it is found that this fluid pressure is exactly 

 that which is requisite to overcome the centrifugal force of the water in the wheel, 

 and to bring the water to a state of rest at its exit, the mechanical work due to both 

 halves of the fall being transferred to the wheel during the combined action of the 

 moving water and the moving wheel. In the foregoing statements, the effects of fluid 

 friction, and of some other modifying influences, are, for simplicity, left out of con- 

 sideration. 



TURBXTH'S IVTINERAI, or TTTRPETH MINERAX.. The yellow sub- 

 sulphate of mercury, called Queen's Yellow. 



TURF (Peat, Scotch ; Tourbe, Fr. ; Torf, Ger.) consists of vegetable-matter, 

 chiefly of the Moss family, in a state of partial decomposition by the action of water. 

 Cut, during summer, into brick-shaped pieces, and dried, it is extensively used as fuel 

 by the peasantry in every region where it abounds. The dens*e black turf, which 

 forms the lower stratum of a peat moss, is much contaminated with iron, sulphur, 

 sand, &c., while the lighter turf of the upper strata, though nearly pure vegetable- 

 matter, is too bulky for transportation, and too porous for factory fuel. These defects 

 have been removed, several processes having been patented for converting the 

 lightest and poorest beds of peat-moss, or bog, into the four following products : 1. A 

 brown combustible solid, denser than oak ; 2. A charcoal, twice as compact as that of 

 hard wood ; 3. A factitious coal ; and 4. A factitious coke : each of which possesses 

 very valuable properties. 



Mr. D'Ernst, artificer of fireworks to Vauxhall, proved, by the severe test of 

 coloured fires, that turf-charcoal is 20 per cent, more combustible than that of oak. 

 Mr. Oldham, engineer of the Bank of England, applied it in softening his steel plates 

 and dies, with remarkable success. A prospect was thus opened up of turning to 

 admirable account the unprofitable bogs of Ireland ; and of producing, from their 

 inexhaustible stores, a superior fuel for every purpose of arts and engineering. 



The turf is treated as follows : Immediately after being dug, it is triturated under 

 revolving edge-wheels, faced with iron plates perforated all over their surface, and is 

 forced by the pressure through these apertures, till it becomes a species of pap, which 

 is freed from the greater part of its moisture by squeezing in a hydraulic press between 

 layers of caya-cloth ; then dried, and coked in suitable ovens. (See CHARCOAL, and 

 COKE.) Mr. Williams, by his patent, makes his factitious coal by incorporating with 

 pitch or resin, melted in a cauldron, as much of the above charcoal, ground to powder, 

 as will form a doughy mass, which is moulded into bricks in its hot and plastic state. 

 It has been found preferable to all other fuel for case-hardening iron, tempering steel, 

 forging horse-shoes, and welding gun-barrels. Since turf is partially carbonised in its 

 native state, when it is condensed by the hydraulic press, and fully charred, it affords 

 a charcoal superior in calorific power to the porous substance obtained from wood. 

 For recent modes of utilising peat, see PEAT. 



TURKEY RED is the name given to one of the most beautiful and durable of 

 known dyes. The art of dyeing cotton with this colour seems to have originated in 

 India. In his 'Philosophy of Permanent Colours,' Bancroft has given a detailed 

 account of the process as practised in that country ; and this process will be found to 

 agree in all essential particulars with that pursued by the Turkey-red dyers of 

 Europe, except that in India the chaya-root is employed as the dyeing material in the 

 place of madder. In the middle ages the art was practised in various parts of Turkey 

 and Greece, especially in the neighboiirhood of Adrianople, and hence this colour is 

 often called Adrianople Bed. Even as late as the end of last century the manufacture 

 of Turkey-red yarn seems to have been extensively carried on at Ambelakia and 

 other places in the neighbourhood of Larissa. An interesting account of the manufac- 

 tures and trade of this then flourishing district, by. Felix, will be found in the Annales 

 de Chimie, t. xxi. 1799. About the middle of last century the art of Turkey-red 

 dyeing was introduced into France by means of dyers brought over from recce. The 



