['243', '(#315)', '############################################', 'PRINCIPLES', 'AND', 'PRACTICE', '>', 'heart-wheel', 'action', '(Fig.', '72A,', 'p.', '249)', 'will', 'bind', 'in', 'the', 'beard', 'of', 'the', 'bobbin,', 'but', 'will', 'not', 'result', 'in', 'a', 'smarter', 'yarn', 'being', 'spun.', 'This', 'gain,', 'however,', 'is', 'usually', 'well', 'worth', 'considering.', 'It', 'will', 'be', 'noted', 'that', 'the', 'spindle', 'speed', 'in', 'all', 'spinning', 'frames', 'is', 'the', 'limit', 'of', 'production,', 'the', 'delivery', 'of', 'the', 'front', 'rollers', 'being', 'controlled', 'to', 'give', 'the', 'required', 'turns', 'per', 'inch', 'of', 'twist.', 'This', 'necessitates', 'the', 'back-rollers', 'being', 'driven', 'from', 'the', 'front', 'rollers', 'or', 'else', 'every', 'modifica-', 'tion', 'in', 'the', 'twist', 'would', 'be', 'accompanied', 'by', 'a', 'modifica-', 'tion', 'in', 'the', 'draft.', 'From', 'the', 'plan', 'of', 'the', 'flyer', 'frame', 'given', 'in', 'Fig.', '69', 'the', 'necessary', 'changing', 'for', 'draft', 'will', 'be', 'realized,', 'and', 'also', 'the', 'conditions', 'of', 'regulating', 'the', 'twist.', 'The', 'cap', 'spindle', '(Fig.', '68b)', 'is', 'in', 'a', 'manner', 'the', 'reverse', 'of', 'the', 'flyer,', 'the', 'bobbin', 'being', 'driven', 'and', 'winding', 'the', 'the', 'yarn--as', 'delivered', 'from', 'the', 'front', 'rollers-upon', 'itself', 'by', 'the', 'action', 'of', 'the', 'air', 'friction', 'and', 'possibly', 'the', 'friction', 'of', 'the', 'yarn', 'on', 'edge', 'of', 'the', 'cap.', 'Thus', 'in', 'this', 'type', 'of', 'frame', 'the', 'spindles', 'must', 'be', 'driven', 'at', 'a', 'high', 'speed', '(at', 'least', '4,000', 'revolutions', 'per', 'minute', 'and', 'up', 'to', '7,000),', 'otherwise', 'the', 'yarn', 'will', 'be', 'softly', 'and', 'insecurely', 'wound', 'on', 'to', 'the', 'spool.', 'This', 'is', 'probably', 'the', 'most', '"natural"', 'method', 'of', 'all', 'the', 'spinning', 'methods.', 'It', 'is', 'curious', 'to', 'note', 'that', 'while', 'cap', 'spinning', 'has', 'become', 'the', 'method', 'of', 'spinning', 'par', 'excellence', 'for', 'fine', 'Botany', 'and', 'cross-bred', 'yarns', 'it', 'has', 'never', 'proved', 'successful', 'for', 'cotton', 'yarns.', 'This', 'fact', 'again', 'suggests', 'how', 'little', 'is', 'really', 'known', 'about', 'spinning', 'principles,', 'It', 'is', 'obvious', 'that', 'the', 'shape', 'of', 'the', 'cap', 'will', 'be', 'varied', 'to', 'meet', 'two', 'exigencies,', 'viz.', ':', 'shape', 'of', 'bobbin', ';', 'delicacy', 'of', 'thread', 'frictioning.', 'The', 'double-headed', 'bobbin', 'will', 'require', 'a', 'cap', 'shaped', '243']
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