| 1 | A | B | C | D |
| --- | --- | --- | --- | --- |
| 2 | Rolla (1805 ship) - Merchantman again, and fate |  |  |  |
| 3 | Launch year | Master | Owner | Trade |
| 4 | 1811 | A. Gordon | Conyers and Nixon | Falmouth-Senegal |
| 5 | 1812 | A. Gooden J. Forbes | Nixon & Co. | London-Grenada London-Mogadore |
| 6 | 1813 | R. Douglas | Nixon & Co. | London-Malta |
| 7 | 1814 | R. Douglas W. Gray | Nixon & C9. | London-Corunna |
| 8 | 1815 | W. Grey J. Wallace | Hodgson | London–Gibraltar London-New York |
| 9 | 1816 | J. Wallace Anderson | M'Guire | London-New York London-Brazils |
| 10 | 1817 | - | Lloyd's Register not published | - |
| 11 | 1818 | Cowley | Hancock | Liverpool-Brazils |
| 12 | 1819 | Cowley | Hancock | Liverpool-Brazils |
| 13 | 1820 | Cowley | Hancock | Liverpool-Brazils |
| 14 | 1821 | Cowley | Hancock | Liverpool-Brazils |
| 15 | 1822 | Cowley | Hancock | Liverpool-Brazils |
| 16 | 1823 | Cowley | Hancock | Liverpool-Brazils |
| 17 | 1824 | Cowley | Hancock | Liverpool-Brazils |

Question: What happened when Rolla's trade became Liverpool-Brazils?
Answer: After Rolla's trade became Liverpool-Brazils in 1818, Rolla's master changed from J. Wallace Anderson to Cowley and Rolla's owner changed from M'Guire to Hancock.