The author measured the fatigue of female spinners which was caused by the increase of their spinning machines by the fatigue-measuring method of precipitin reaction of urine. As the result of that test, the increase of fatigue was not observed in both of them who handled 5.5 machines(40. S) and 3.5 machines (20. S). The author observed the increase of fatigue in them who laboured for two months with 20 weaving looms (No. 215).