Page:Popular Science Monthly Volume 90.djvu/79

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Popular Science Monthly


��Americans quickly noted that while all the raw material for rope, the world over, came from Manila, little factor>'- finished rope was going abroad. As a result an American com- pany was formed and a modern plant for rope-making was built in Manila.

A good hemp rope is hard, but pliant, yellowish or green- ish gray in color, with a certain silvery or pearly luster. A dark or blackish color indicates that the hemp has suffered from fermentation in the pro- cess of curing, and brown spots show that the rope was spun while the fibers were damp, and is consequently weak and soft in those places. Sometimes a rope is made of inferior hemp on the outside, covered with yarn of good material. This may be detected by dissecting a portion of the rope. Other inferior ropes are made from short fibers, or with strands of unequal lengths or uneven spinning, the rope in the first place appearing woolly, on account of the ends of the fibers projecting; in the latter case the irregularity of manufacture is evident on inspection.

A test for ascertaining the purity of Manila rope consists in forming balls of loose fiber of the ropes to be tested and burning them com- pletely to ashes; pure Ma-

����The na:i-.c5 do make rope but it is too loosely woven to have much commercial value. An American plant has now been established in Manila and modern machinery installed

��nila burns to a dull grayish-black ash ; sisal leaves a whitish-gray ash; a combination of Manila and sisal yields a mixed ash. Manila hemp is frequently adulterated with New Zealand flax and Russian hemp, both of which are much inferior in strength. Rope in service deteriorates in two ways: the wear on the outer surface, which can be readily seen and the stretching, bend- ing, crushing and breaking of the inner fibers, which cannot be discovered without a careful examination. It is when rope is to be subjected to such severe bending and rough treatment that preliminary oiling of the fibers is important, if the life of the rope is to be long.


����Cargoes of hemp ready for shipment to England and western ports. All the raw material for rope comes from Manila, except certain inferior grades made from flax and Russian hemp

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