Note 12 — Chapter III
Reading edition
In the actual case observed, the ripples unsmoothed had a wave-length of about 2-1/2 inches; and when the new ones were first formed, there were about 30 ridges in the length originally traversed by 15 or 16.
Reading edition
In the actual case observed, the ripples unsmoothed had a wave-length of about 2-1/2 inches; and when the new ones were first formed, there were about 30 ridges in the length originally traversed by 15 or 16.