THE CUBA REVIEW 



31 



fact that its manufacturers have been 

 working to their full capacity filling the 

 orders received from the chemical indus- 

 tries, and that the sugar factories have 

 only recently been brought face to face 

 with the necessity of finding some other 

 material than cotton for use in filtration. 



The chemical industries have to deal 

 with a much wider range of difficult 

 filtering problems than the sugar manu- 

 facturers, and their uses of filter cloth 

 are accordingly more diverse; few of 

 them, however, are confronted with the 

 necessity for filtration of such quantities 

 of strong alkaline solutions as the pro- 

 cess of beet sugar manufacture requires, 

 or use such large amounts of material. 

 Both hot and cold saccharate solutions 

 are handled in enormous volumes in the 

 Steffens house departments of the fac- 

 tories. 



The problem of adapting the metallic 

 cloth to the uses of the sugar industry is 

 not, however, an entirely simple one. It 

 is complicated by the fact that metallic 

 cloth is not readily adaptable to plate and 

 flame filters, such as are employed in 

 many sugar factories. Its introduction, 

 therefore, must be accompanied in those 

 plants by a change in the filtering ma- 

 chines used. This condition is not with- 

 out its advantages, however, for metallic 

 cloth is too high in its first cost to be 

 profitably used except in modern leaf 

 filters which are rapid in operation and 

 of large capacity, and thus possess the 

 maximum usefulness per unit of filter 

 area. 



It is not good economic practice to in- 

 stall metallic cloth in an inefficient ma- 

 chine, because only one-third to one- 

 fourth as much cloth is required in one 

 of modern type, and the saving in first 

 cost of the cloth will go toward paying 

 for one of more efficient modern type far 

 greater convenience and economy of labor 

 result from the use of modern equipment. 



Simple in Construction. 



In its construction the metallic cloth 

 which has proved such a marked success 

 in its field, where ordinary wire gauge 

 had been found entirely inadequate, is as 



simple as it is novel. It is made of ex- 

 tremely fine Monel wire, which is non- 

 corrosive, and the wires are first stranded 

 before weaving, just as the threads of 

 cotton are stranded and twisted into cords 

 before weaving. Stranding the tiny wire 

 into loosely twisted cables before it enters 

 into the warp and weft of the cloth has 

 the effect of giving great strength and 

 flexibility, as well as fitness of texture, 

 to the cloth, and filtration takes place 

 through the strands as well as through 

 the interstices between them. The fin- 

 ishing touch is put on the fabric by run- 

 ning it between calendaring rolls which 

 reduces the size of the openings and gives 

 it a smooth surface which is easily 

 cleaned, and from which the filter cake 

 slides readily in discharging. 



This metallic cloth, which seems to 

 offer great promise in reducing Steffens 

 house operating expenses, is broadly cov- 

 ered by United States patent No. 1,147,- 

 279, and is sold solely by the United 

 Filters Corporation, or its accredited 

 agents. Incidentally, the Franklin Insti- 

 tute of Philadelphia recently awarded Mr. 

 Sweetland a certificate of merit for his 

 cloth. — Facts About Sugar. 



PORTO RICAN LABORERS 



Efforts of Cuban planters to import 

 Porto Rican labores for work in Cuban 

 cane fields have failed. The Cuban plant- 

 ers offered $2.00 per day with no extra 

 pay for overtime work. The Porto Rican 

 employment service replied demanding 

 time and half pay for overtime, free 

 transportation to Cuba and return, free 

 housing and no discrimination as regards 

 color. Cuban planters characterize these 

 terms as prohibitive. 



CHINESE LABORERS 



Of two hundred Chinese laborers who 

 were taken to Cuba under the new law of 

 immigration a short time ago to work at 

 the Central Santa Lucia in Oriente, there 

 remain eighty in the Immigration Camp 

 at Triscornia who refuse to work and who 

 will be deported. 



