Who is Goblin and what does he have to do with Johnny's new job?

Rab shows him how to ride the company horse, Goblin. Goblin is a good horse, but he spooks easily because his previous owners whipped him. After one lesson from Rab, Johnny continues to take Goblin to practice riding in Boston Common. Over time, he becomes very good at riding the notoriously difficult horse, earning praise from Uncle Lorne. Johnny begins to deliver The Boston Observer to the neighboring towns, and enjoys discussing politics with the people he meets.