Read it through once

These points being settled, I next bethought me of the nature of my refrain. Since its application was to be repeatedly varied, it was clear that the refrain itself must be brief, for there would have been an insurmountable difficulty in frequent variations of application in any sentence of length. In proportion to the brevity of the sentence, would, of course, be the facility of the variation. This led me at once to a single word as the best refrain.