. A dictionary of arts, manufactures and mines : containing a clear exposition of their principles and practice. lers covered with flannel are occasionallyOipplled. Were the drawing of a riband continued till all its fibres acquired the desired degreeof parallelism, it would be apt, from excessive attenuation, to tear across, and therebyto defeat the purpose of the spinner. This dilemma is got rid of in a very simple way,namely, by laying several ribands together at every repetition of the process, and incor-porating them by the pressure of the rollers. This practice is called doubling. It is
. A dictionary of arts, manufactures and mines : containing a clear exposition of their principles and practice. lers covered with flannel are occasionallyOipplled. Were the drawing of a riband continued till all its fibres acquired the desired degreeof parallelism, it would be apt, from excessive attenuation, to tear across, and therebyto defeat the purpose of the spinner. This dilemma is got rid of in a very simple way,namely, by laying several ribands together at every repetition of the process, and incor-porating them by the pressure of the rollers. This practice is called doubling. It is anexact imitation of what takes place when we draw a tuft of cotton wool between ourfingers and thumb in order to ascertain the length of the staple, and replace the drawnfilaments over each other, and thus draw them forth asain and again, till they are allparallel and of nearly equal length. The doubling has another advantage, that of causingthe inequalities of thickness in the ribands to disappear, by applying theii- thicker to theirthinner portions, and thereby producing uniformity of substance. 329 y 11.
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Keywords: ., bookcentury1800, bookdecade1840, booksubje, booksubjecttechnology
