Page:Popular Science Monthly Volume 63.djvu/538

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IFTEEN years ago, Professor L. A. Sherman, of the University of Nebraska, while investigating the sentence-lengths used by early and modern English writers, noticed that in the works which he examined each author manifested an average sentence-length, which he inferred to be characteristic of the author. Consecutive hundreds of periods were averaged with respect to the number of words per sentence and the mean of five or more of these averages was taken to represent approximately the average sentence-length used by the author. It was found that the averages for separate hundreds generally varied by less than 20 per cent, from the total average of 500 to 1,000 sentences. The 2,225 periods of De Quincey's 'Opium-Eater' averaged 33.65 ± 6.64 words per sentence, where the number 6.64 indicates the largest number of words by which the averages of individual hundreds differ from the average 33.65. Similarly 722 periods from Macaulay's 'Essay on History' yielded 23 ± 3.35 words per sentence, 750 periods from Channing's 'Self-Culture' 25.35 ± 1.45, 732 periods from Emerson's 'American Scholar' and the 'Divinity School Address' 20.71 ± 2.65 and 805 periods from Bartol's 'Radicalism' and 'Father Taylor' gave an average of 16.63 ± 2.35 words per sentence. These results led to the suspicion that stylists are 'subject to a rigid rhythmic law from which even by the widest range and variety of sentence length and form they may not escape.' Averages from other authors were made with similar results. A culminating test was furnished by actually counting the words in each of the 41,500 periods in the five volumes of Macaulay's 'History of England' with the resulting average of 23.43 ±7.11. The conclusion was that writers who have achieved a style are governed by a constant sentence rhythm, which will generally be revealed by an examination of 300 periods.

Encouraged by these results. Professor Sherman induced Mr. Gerwig, then a student at the University of Nebraska, to examine other stylistic peculiarities. This Mr. Gerwig did by determining the average number of predications per sentence and the percentage of simple sentences used by one hundred different authors. His conclusions are summed up in the following words: "A very little investigation served to convince me that the same remarkable uniformity which had been