A correspondent writing Monday eve. says John McDOWELL who was so badly scalded at the explosion in Snowball's Mill on Saturday eve., died the same night. Robert SWEEZY died on Sunday, making four in all who lost their lives by the explosion. Mr. WHITEHEAD and two others were slightly injured. They were all men with families except Sweezy. Twelve feet of one of the boilers was blown right out of its bed, killing ROSS and POWER instantly. - The body of the engineer Peter ROLAND who was drowned at Chatham (North. Co.) on Saturday morn. 4 o'clock, is not yet found. He leaves a wife and seven children.