On February 8, Leggett sent a telegram offering to sell Picarro a personal computer. Picarro received the telegram the same day (February 8). Picarro mailed a letter of acceptance on February 9 at 11 a. m., which reached Leggett on the afternoon of February 12. At 1: 30 p. m. on February 9, Picarro received a telegram from Leggett revoking the offer. Was the revocation effective?