Rapid‐run magnetograms from the U. S. Coast and Geodetic Survey (USC&GS) and from other observatories located near the magnetic equator were used to study sudden commencements that occurred during the period October 1957 to September 1958. Analysis of these magnetograms yielded three important results: (1) the sudden commencement always occurred first in high or middle latitudes; (2) Little America, Antarctica, registered the sudden commencement first or second 85 per cent of the time; and (3) the apparent propagation velocities of the sudden commencement around the magnetic equator had average values between 1145 and 2835 km/se