(Woods Hole Oceanographic Institution, 1947-09-15)
Barbour, Lucius Hilliard
The first sounds to arrive at the receiver commence at low intensity and with long intervals between them. Gradually 1 the interval shortens, the sounds become louder until they blend in to one loud sound which ceases abruptly. This peak cut-off is so marked, that when recorded on suitable equipment synchronized with an accurate time piece, the instant of its occurrence may be determined within an accuracy of .01 seconds. In this report, all computations will be based on this interval as a limit of accuracy attainable.