Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Who was the vacator when the successor was formally installed on February 1, 1871?

### Inputs:
table_name: table, columns: ['State (class)', 'Vacator', 'Reason for change', 'Successor', 'Date of successors formal installation']

### Response:
SELECT Vacator FROM table WHERE Date of successors formal installation = February 1, 1871