The New York Sunday Mercury of the 25th October publishes a rather sensational report of a rock in the middle of the At lantic Ocean as a solution to the mystery regarding the fate of the steamer* City of Boston, President, Pacific, United King dom, The Ismailia, and other vessels that have never been heard from after leaving port. The rock, it appearn, lies in latitude 40deg N, and longitude G2deg 183ecs. It was discovered by Captain Pevasso, of the barque Teroia, which arrived at Queens town 2nd October fiomNew York. Cap tain Pevasso makes the following report of his discovery : — On the 9th September , at three p m., wind north, very light and clear weather, with a sea perfectly smooth, observed on the horizon a large rock, about four miles to windward, in lat. 40 N., long. 62deg 18secs west. Tried to beat up to it, but owing to the lightness of the wind could Dot do so. The rock lay north and south, and was of a reddish brown colour. Discovered seaweed on it plainly with a glass. The dimensions are as follows : — Length, 100 metres, 3ft 3£in per metre. On south part 10 metres broad, and about 5 metres out of water, which was low. About 2.45 p.m. the rock was bare, north, and we laid by. By chronometer calculation the rock was in' the exact position, lat. 40deg. N., long. 62deg. 18min. W. Captain Pevasso states that he has a chart of 1848, by Noneyson, on board, with this rock marked on it ; but there are two degrees difference in the longitude. This, he says, is accounted for by the incorrectness of the old chron ometers. He was surprised at not find ing this rock" on an English chart, by Wilßon, dated 1872, and also on a Freuoh chart of the same date, which he has on board He states that he tried for sound ings, but could get none iii the vicini'y of the rock. According to Captain Pevaaso's report, the rock is within a few seconds of same degree as New York is situated in, and on a straight line from west to east, lying about 550 miles from the har bour, and directly in the course of ocean steamers, in what is known as the south ern passage. 