less pristine interior cry. Measure th.
As alraigionmakes it sound. Meteorites are not abundant and meteoritic samples not especially easy to get tecreme andneeded muc. Above all, t Patterson’s samples inuously and unaccountably contaminated mospo air. It eventually led o create a sterile laboratory—t, according to at least one account.
It took Patterson seven years of patient to assemble suitable samples for finaltesting. In traveled to tional Laboratory in Illinois,ime on a late-model mass spectrograpectingand measuring te quantities of uranium and lead locked up in ancient crystals. last s, Patterson ed t raigo o a al because attack.
Soon after a meeting in isconsin, Patterson announced a definitive age for t standsuncer,” as McGrayne admiringly notes. After th finally had an age.
terson nourned tention to tion of all tlead in tmospounded to find t tle tsof lead on invariably surprisingly, y years every study of lead’s effects urers of lead additives.
In one sucudy, a doctor o breated quantities. tested. Unfortunately, as torappears not to excreted as a e product. Rat accumulates int’s so dangerous—and neitested. In consequence, lead was given a clean bill of h.
Patterson quickly establis mospill do, in fact,since lead never goes a about 90 percent of it appeared to come fromautomobile ex pipes, but prove it. o comparelead levels in tmosp existed before 1923, raetroduced. It occurred to ice cores could provide the answer.
It snoes into discrete annual layers(because seasonal temperature differences produce sligion from er tosummer). By counting back t of lead in eac global lead concentrations at any time for ion became tion of ice core studies, on wological work is based.
Patterson found before 1923 t no lead in tmosp since t time its level eadily and dangerously. to get lead taken out of gasoline. to t end, ant and often vocalcritic of try and its interests.
It o be a ion s director