Written records of natural phenomena come from personal journals and diaries, newspaper accounts, ship logs and government documents, among other sources. Such accounts often offer descriptive details and context that cannot be matched by other methods, and they can prove extremely useful in broadening records both temporally and geographically. Given that they predate the sort of widespread instrumental readings that scientists have come to depend on, sometimes there is simply — and literally — no substitute for historical data. Despite their advantages, historical records are used infrequently in modern physical sciences. That may be changing, however.