MECHANICS AND USEFUL ARTS. 63 



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lb. over the present method, and leaves the sugar so thoroughly free 

 from molasses that no loss is made by drainage in shipping. 



APPLICATIONS OF CENTRIFUGAL ACTION TO MANUFACTURING PURPOSES. 



IT is well known that a centrifugal machine has been hitherto em- 

 ployed with much advantage for the drying of textile fabrics and for 

 clarifying sugar ; but these are not the only purposes to which it is 

 adapted ; for every day new applications of this apparatus sug- 

 gest themselves, and important problems are solved by its means. 

 We now learn that one of the most important operations of brewing 

 may be wonderfully simplified by the use of a centrifugal apparatus. 

 It has been hitherto considered extremely difficult to reduce the tem- 

 perature of beer to the degree of coolness requisite ; it has been neces- 

 sary to make use of refrigerators for this purpose, and, notwithstanding 

 all precautions, mistakes not unfrequently happen. It occurred to some 

 English brewers that this difficult cooling process might be effected by 

 means of a centrifugal machine. This idea has been put in practice 

 with complete success. The beer was reduced to the desired tempera- 

 ture by merely passing it through the machine ; and this was effected 

 not only with great rapidity, but also with considerable economy. 

 Some time back, M. Touche, of Paris, endeavored to produce ice by 

 means of a hydrofugal apparatus. He did not succeed in reducing 

 water to the freezing point, but he cooled it to a degree far below that 

 required in brewing beer. It would be superfluous to explain these 

 results, for every one is acquainted with the effects of a very rapid ven- 

 tilation, and the centrifugal machines are made to rotate at the rate of 

 3000 revolutions per minute, and even quicker. We are further informed 

 that in certain manufactories in Alsace a hydrofugal machine is used 

 for making starch. When the flour is stirred about in water, the dif- 

 ferent substances range themselves according to their specific gravities, 

 unless prevented by some peculiar circumstances. Now, this is pre- 

 cisely the result obtained by the centrifugal machine ; starch, being 

 the heaviest substance, separates itself from the others, and is first 

 precipitated. The centrifugal machine may also be advantageously 

 applied for classifying grain, seed or ores, according to their respective 

 densities, whether liquid or solid, provided that they are not of a 

 cohesive nature, or that whatever cohesiveness they possess may bo 

 easily removed. In fact, the centrifugal apparatus may be applied to 

 so many different manufactures, that it may justly be looked upon as 

 one of the most fortunate and fruitful inventions of modern times. 

 Moniteur Indus triel. 



GWYNNE'S CENTRIFUGAL PUMP. 



IN this pump, the discs of the piston are of concave form, the hollow 

 parts beino; placed immediately opposite to each other. An impeller, 

 radiating from a boss or hollow axis, is fixed between the two discs, 

 and mounted on a shaft, which may be placed at any required angle ; 

 the narrowest part of the impeller is at the outer edge of the piston, 



