RHOSCOLYN, ANGLESEY.—A very thick fog prevailed here on the night of the 15th June, and at about 5.30 on the following morning the coxswain of the Life-boat, who had been watching during the night, heard voices close to the signal and look-out station. He, as soon as possible, fired signals to summon the crew, and putting off with others in small boats found the s.s. Avon, bound for Liverpool with fire-clay, stranded on the rocks under the flagstaff, but the captain declined any assistance. Shortly after seven o'clock the sea, which had been up to that time smooth, became lumpy and dangerous for the small boats, and it was therefore decided to return to the shore and take out the Life-boat Ramon Cabrera to stand by the steamer in case she should get free of the rocks with the-rising'tide and her crew be in danger, it having been stated that the ship was leaking. Just as the Life-boat arrived the steamer floated, hoisted her two boats which had been lowered, and proceeded on her journey. The Life-boat followed her until she was out of the bay..