The only person who could accurately preserve large numbers of exotic languages would be someone with an extraordinary ear who was physically robust and willing to devote 18 hours a day to data collection, and who cared so little for academic prestige that he would not spend the time necessary to prepare his material for publication. In addition, he would have to find an institution that would support him.
Americanists can thank the gods for providing them with such an impossible combination in the person of John Peabody Harrington.