GUYSBOROUGH. July 29 - The American ship Union, 549 tons, of Bath, Me. Isaac A Pannell, master, from New York for Bio. St. Lawrence, 15 days out, in ballast, went ashore during thick weather, on Tuesday morning, 25th inst., on the Big Ledge, at the entrance of White Head Harbour. Vessel condemned. Materials and Hull, to be sold on the 3rd of August. Capt and crew arrived at Pictou.