Hi Pat, there is a large mansion called Bowood House situated between Chippenham and Calne in Wiltshire. Famous by the end of the 18th century for it's links with art, science and literature, Joseph Priestly was staying here when he discovered oxygen about 1775. In fact his friend, William Petty, built a laboratory for Priestly at Bowood house.
Do you have any evidence that Peter Brewer was born in Bath or something to suggest he was not? Any information you may have about his uncle may prove useful in tracing Peter. For example his name, where he lived, occupation etc. He may have worked at Bowood or lived close by which may have made an impression and encouraged Peter to name his house in memory.
Perhaps the passenger list for the Heroine may state where Peter was from.
Cheers Dave