The Monk's logbook

The Time Lord the Monk kept a logbook, a "sort of diary".

It was recovered by Steven Taylor and Vicki Pallister in his own TARDIS.

They managed to read that:
 * he had met Leonardo da Vinci and discussed with him the principles of powered flight;
 * he had put two hundred pounds in a London bank in 1968, he had nipped forward two hundred years and collected a fortune in compound interest. (TV: The Time Meddler)