696 REFRIGERATION OF WORTS 



of all Europe ; but in Scotland it has been adopted as the regulator of her cotton- 

 manufactures. 



The number of threads in the warp of a web is generally ascertained with con- 

 siderable precision by means of a small magnifying glass, fitted into a socket of 

 brass, under which is drilled a small round hole in the bottom plate of the standard. 

 The number of threads visible in this perforation ascertains the number of threads in 

 the standard measure of the roed. Those used in Scotland have sometimes four 

 perforations, over any one of which the glass may be shifted. The first perforation 

 is j of an inch in diameter, and is therefore well adapted to the Stockport mode of 

 counting ; that is to say, for ascertaining the number of ends or threads per inch, 

 the second is adapted for the Holland reed, being ^th part of 40 inches ; the third 

 is ^th of 37 inches, and is adapted for the now almost universal construction of 

 Scotch reeds; and the fourth, being ^th of 34 inches, is intended for the French 

 cambrics. Every thread appearing in these respective measures, of course, represents 

 200 threads or 100 splits, in the standard breadth ; and thus the quality of the 

 fabric may be ascertained with considerable precision, even after the cloth has under- 

 gone repeated wettings, either at the bleaching-ground or dye-work. By counting the 

 other way, the proportion which the woof bears to the warp is also known, and this 

 forms the chief use of the glass to the manufacturer and operative weaver, both of 

 whom are previously acquainted with the exact measure of the reed. 



REFINERY SXiAG. The cinders produced in the process of refining iron. 

 See IEON. 



REFUTING. In metallurgy, the process of partially decarbonising pig- iron. The 

 processes employed to obtain pure metals from regulus, or impure mixtures. 



REFINING GOLD AND SILVER. See GrOLD. 



REFRACTORY lYXINERAXiS. Such minerals as graphite or plumbago, 

 mica, steatite, fire-clays, and the like, which endure without fusion a very high 

 temperature. See FiBE-CiAY. 



REFRIGERATION OF WORTS, &,c. It is of great importance to effect 

 the cooling of worts as rapidly as possible. The simplest mode of refrigeration is 

 by exposing the hot liquor or wort in shallow vessels, called coolers, to the action of 

 the atmosphere or a current of air, sometimes accelerated by fans rotating horizontally 

 just above the surface of the liquor ; but sometimes utensils called refrigerators are 

 employed, and so constructed that a quantity of cold water should be brought into 

 contact with the heated fluid. 



A simple form of refrigerator is that of the worm used by distillers; and the 

 reverse process is commonly used by brewers, viz. a stream of cold water passing 

 through pipes in a zigzag form, laid horizontally in the shallow cooler. But in every 

 construction of refrigerator heretofore used, the quantity of cold water necessarily 

 employed in the operation, greatly exceeded the quantity of the fluid cooled, which, 

 in some situations, where water cannot be readily obtained, was a serious impediment 

 and objection to the use of such apparatus. 



In August 1826, Mr. Yandall obtained a patent for an apparatus designed for 

 cooling -worts and other hot fluids, without exposing them to evaporation ; and con- 

 trived a mode of constructing a refrigerator so that any quantity of wort or other 

 hot fluid may be cooled by an equal quantity of cool water ; the process being per- 

 formed with great expedition, simply by passing the two fluids through very narrow 

 passages, in opposite directions, so that a thin stratum of hot wort is brought into 

 contact over a large surface with an equally thin stratum of cold water, in such manner 

 that the heated water, when about to be discharged, still absorbs heat from the hottest 

 portion of the wort, which as it flows through the apparatus is continually parting 

 with its heat to water of a lower temperature flowing in the contrary direction ; and 

 however varied may be the form, the same principle should be observed. 



Figs. 1702, 1704, 1705, represent different forms in which the apparatus might 

 be made; the two first having zigzag passages; the third, channels running in 

 convolute curves. These channels or passages are of very small capacity in thickness, 

 but of great length, and of any breadth that may be required, according to the quantity 

 of fluid intended to be cooled or heated. 



Fig. 1703 is the section of a portion of the apparatus shown a&figs. 1702 and 1705 

 upon an enlarged scale ; it is made by connecting three sheets of copper or any other 

 thin metallic plates together, leaving parallel spaces between each plate for the pas- 

 sage of the fluids, represented by the black lines. 



These spaces are formed by introducing between the plates thin straps, ribs, or 

 portions of metal, to keep them asunder, by which means very thin channels are pro- 

 duced, and through these channels the fluids are intended to be passed, the cold 

 liquor running in one direction, and the hot in the reverse direction. 



Supposing that the passages for the fluids are each one-eighth of an inch thick, 



