1. cabot, sebastian son of the preceding, born either in Venice or Bristol; accompanied his father to N. America; sought service as a navigator, first in Spainthen in England, but failed; returned to Spain; attempted under Charles V. to plant colonies in Brazil with no success, for which he was imprisoned and banished; was the first to notice the variation of the magnetic needle, and to open up to Englandtrade with Russia (1474-1557).