"I suppose it is when you stop to think of it," Hal answered. "Well, anyhow, that's what a sliver is. In some mills they draw the cotton out into these long strands and double together four or eight slivers before they are carded. The carding lengthens or stretches them to the size of one and therefore you get a greater uniformity of size. Beside that, all the crossed or snarled fibers are arranged so that they lie out straight and smooth, and when this is done the material is ready for the bobbin and fly frames." "And what, for goodness' sake, might those be?" demanded Captain Dillingham. "I certainly am a great hero coming here and knowing so much," Hal answered with amusement. "I think you will understand them better, sir, if you forget what they're called and remember only what they do. They actually combine three processes: slubbing, intermediate, and roving, and their aim is to draw the sliver out until it is thinner, more uniform, and cleaner for spinning. Surely that is simple enough. The spinning is done on a mule or a ring frame--sometimes the one is preferred, sometimes the other. Generally speaking, the thread from one of these machines is what is used for weaving purposes. Sometimes, though, it happens that an order comes for a crackajack fine yarn of the best possible quality and then another combing or carding process follows which takes out everything shorter than fibers of a specified length. As a result about seventeen per cent. of waste is thrown out, as great a percentage as in all the other processes put together. Naturally it is a pretty expensive operation and it makes the yarn thus turned out high in price." "I suppose such yarn goes only into the finest quality goods," observed Captain Dillingham. "Exactly!" was Hal's answer. "It all sounds simple as rolling off a log," Carl affirmed. "If it seems so to you, just you think back over the problem Arkwright and some of the other inventors, the fruit of whose labors we are now reaping, had to solve," put in Uncle Frederick. "Even I, who am ignorant as an Egyptian mummy concerning cotton manufacture, can appreciate to some extent what they were up against. You must remember that no material is stronger than its weakest part. You have, for instance, a thin place in a string; it matters not how strong that string may be in other spots; pull it taut and it will snap. The thick places do not help make the string strong as a whole. So it is with thread. You have to draw it out until every portion of it is as strong as every other--a pretty little conundrum! It is the drawing, twisting, and doubling which makes the thread first uniform and then strong. Try working-out devices that shall do all these things--devices that shall twist and then double without untwisting, for example. You'll find it worse than a three-ringed circus."