At the end of the Nineteenth century William Ramsay, searching for minerals that might concentrate argon or helium, wrote, “One mineral—malacone—gave appreciable quantities of argon; and it is noteworthy that argon was not found except in it (and, curiously, in much larger amount than helium), and in a specimen of meteoric iron. Other specimens of meteoric iron were examined, but were found to contain mainly hydrogen, with no trace of either argon or helium. It is probable that the sources of meteorites might be traced in this manner, and that each could be relegated to its particular swarm.” Finally, sixty years later, this is what Ollie Schaeffer and I now set out to do. Meteoritic iron has been used since prehistoric times: necklaces of the metal beads interlaced with gold are found in the tombs of Egyptian kings, and an inventory of a Hittite temple, describing where on earth their gold and silver came from, lists their iron as having “fallen from the sky.” Yet as late as the early nineteenth century, the reality of meteorites still was not accepted by men of good will. For after all, how could heavy stones and chunks of iron fall out of the sky? And then in 1803 a huge shower of meteorites fell at L’Aigle, France, just at the time that the French Academy of Sciences had convened a meeting to discuss the question. In America no one paid much attention, until on December 14, 1807, at 6:30 in the morning, a bright fireball suddenly blazed through the sky over Vermont and Massachusetts. It was reportedly nearly as bright and big as the moon, until it suddenly exploded and disappeared over the town of Weston, Connecticut, showering the area with stone fragments, as the local media reported. In those days it took a while for the news to travel a few tens of miles, and so it was a few days before Yale’s new professor of chymistry (sic) and natural history, Benjamin Silliman, heard of it. Grabbing his hat and a colleague, Professor James L. Kingsley, he galloped across the state to Weston.