1x8 
J. E. Wallace Wallin. 
The duration of a given complex-centroid interval in speech will prob¬ 
ably fall somewhere within the limits of 0.14s (= shortest in series, J 
M. T., Table LXV.), and 1.93s (= longest in series, W. L. P., Table 
LXIV. ), a range of about 1 The range for the average interval of 
different records is about of this (from 0.32s, J. K., Table LX. to 
0.75s, A. D. B.a, Table LIX.), and for the averages of different sets of 
records less than \ (from 0.47s, Table LX. to 0.71s, Table LXVIIL ). 
The highest range between the averages of the selections read twice by 
the same person was 0.10s (S. ); the lowest, 0.03s (C. O.). 
The extreme deviations of these intervals from the average were always 
of the nature of excesses. In the measurements 100 %were plus extremes. 
This may be due more to the pauses than the brevity of the average. 
The former enables the range to be extended almost indefinitely, while 
it can be only slightly abbreviated. The extremes for the different sets, 
may be obtained in the e and c columns of the tables. 
The length of the average complex-centroid interval is a: little over half 
a second (0.58s). 
The averages in prose (0.59s) and poetry (0.57s) are practically equal 
in length. The tendency, just barely perceptible, is to make the inter¬ 
vals of prose the longer. This conclusion may only hold for such inter¬ 
vals as were measured, which were prevailingly 2-syllable sound- and 
i -pause-2 -syllable composite-intervals. 
The longest average in any record was 0.07s shorter in prose (0.70s, 
W. L. P.), than in poetry (S., Table LXVIIL); and the shortest 
average was 0.10s shorter in the reading scansion of English poetry (C. 
O., Table LXVII.) than in prose (0.55s, G. A. A.). 
The intervals composed regularly of two syllables (0.71s = average for 
set of Tennyson verses; 0.66s, same for sing-song and doggerel scan¬ 
sion) are longer than those composed of a mixture of one, two, three, 
four and five syllables, provided the number of 1-syllable intervals is 
relatively larger than the number of 3-, 4- and 5-syllable intervals. 
The average inequality of the lengths of complex-centroid intervals in 
all varieties of speech was about o. 17/or 28% of the length of the average- 
The regularity in a given set of records of a variety of verses of 
poetry of the predominantly 2-syllable type, scanned according to the 
fourt ypes of scansion, was about 8 % higher than that for the intervals m 
a given number and variety of sentences of prose, uttered in various 
ways. The irregularity for the former was 22% (Tables LIX., LXI-, 
LXIL, LXIX.) ; of the latter, 30% (Tables LXIV., LXX.). 
The regularity in a given set of records of English poetry, the inter^ 
vais of which are mostly of the 2-syllable pattern, and the scansion