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[and from] palaeoclimatic maps.” Geologic studies would provide “unambiguous,
decisive proof” of “specific palaeoclimatic factors” and trump paleomagnetism. 12
Eachofthepapersintheseven-hundred-pagevolumethatresultedfromthecon-
ference was about ancient climates, not paleomagnetism, so the fight may not have
been entirely fair. But certainly an open-minded person would have concluded
that the evidence from past climates was suggestive enough to keep continental
drift under consideration. Referee Bucher rang the bell and declared the fight over,
physics down for the count. Meanwhile, the decisive event was taking place in a
different arena.
Too Good Not to Be True
In 1964, the Royal Society hosted the second of the two important meetings, “A
Symposium on Continental Drift.” 13 Blackett opened by noting that “During the
30 years from 1920 to 1950, the controversy was often violent and sometimes al-
most abusive.” He compared the disagreement with Bret Harte's account of a dis-
putation on the Stanislaus over whether “some bones dug up by Brown were those
of a very rare animal or of one of his neighbor Jones's lost mules.” The drifters
“had weakened their case by rather weak theorizing about how it might have oc-
curred,”Blackett judged.Ontheotherhand,“the'antidrifters'weakenedtheirown
case by producing theoretical arguments why drift cannot have occurred which
were probably as fallacious . . . as those put forward by the 'drifters.'” 14
Blackett credited Arthur Holmes and his 1944 textbook with “convincing the
early workers in rock magnetism that the probability that the continents had drifted
was high enough to justify an intensive study of the directions of magnetizations
of ancient rock.” He concluded: “The last vestige of doubt that . . . the similarity
of shapes of the two opposing coasts of the Atlantic could not be an accident, was
removed when it was noted that the mid-Atlantic Ridge has the same shape as, and
was equidistant from, both opposing coastlines” (ix).
Runcorn titled his paper “Palaeomagnetic Comparisons Between Europe and
North America.” He said that “a systematic westward displacement, of the order of
20 degrees to 30 degrees, of the [apparent] polar wandering path from American
rocks from that determined from European rocks has been demonstrated.” 15 In-
stead of a fight to the finish, Runcorn saw a consilience of evidence: “The hy-
pothesis of continental drift is supported as being much preferable in view of the
concurrence of palaeomagnetic, palaeoclimatic and geological evidence.” 16 Ken
Creer began with a flat statement: “The considerable palaeomagnetic data from the
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