Jules Verne 
In Search of the Castaways 

After finding a bottle the captain had cast into the ocean after the Britannia is shipwrecked, Lord and Lady Glenarvan of Scotland contact Mary and Robert, the young daughter and son of Captain Grant, through an announcement in a newspaper. The government refuses to launch a rescue expedition, but Lord and Lady Glenarvan, moved by the children’s condition, decide to do it by themselves.