273 (#359) ############################################ PIANI SETS OF MACHINES may only be employed to a very limited extent in draw- ing boxes for "levelling” as distinct from “ reducing." Here again research is necessary to decide whether this method-draft less than doublings-does result in levelling ; some overlookers hold that too little draft is almost as unsatisfactory as too much draft. In the second case, it will be obvious that as doublings and draft exactly balance, the spindlage should be exactly the same from first box to last box. But there a I REV 2 REV etike 2YDS FOR 4 DRAMS-2 DRAMS PER YO E 3 Treen de 123 b 1 REV 4 REVS 4YDS FOR 4 DRAMS: I DRAM PER YO ke at 4 SUVERS TYD. LONG EACH I DRAM. PER YARD EACH dor Syarat с I REV BREVS 8 YDS FOR 4 DRAMS: Y2 DRAM PER YD IST - Fig. 81.-Illustrating principles of Doubling and Drafting in Worsted Spinning TA he i would be no reduction in the thickness of the sliver- it would come out of the last box the same thickness it entered the first box (Fig. 81 (b)). In the third method, the draft of eight would result in the sliver delivered by box 2 (Fig. 81 (c)) being double the length of that delivered by box 1; so that speeds of front rollers being the same the spindlage would have to be increased exactly in accordance with the dominance of draft over doublings, viz., as 4:8. ? 1 S 273
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