Detroit, Aug. 30.- The big exclusive passenger steamship Northwest, owned by the Northern Steamship company, went ashore on Bar Point, Lake Erie, oLE the mouth off the Detroit river. The accident was due to fog. The steamship has over 300 passengers abroad, amoag them being Mayor Bishop aud Postmaster Baker, of Buffalo, and a uuuiber of other Buffalo officials eu route to Detroit on a pleasure trip, The wreeking tug Champion started to the steamsliip's assistance last night. Mayor Pingree and some of the other Detroit officials who had prepared for a reception to tue Buffulo officials have gone to the sceue on the Champion. The Northwest's situation is not believed to be especially dangerous, although the bottom is rocky about the mouth of the river.