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

### Instruction:
Tell me the sum of Gross Tonnage for isis ship on date commisioned less than 1842

### Inputs:
table_name: table, columns: ['Ship', 'Date Commissioned', 'Gross Tonnage', 'Propulsion', 'Material']

### Response:
SELECT SUM Gross Tonnage FROM table WHERE Ship = isis AND Date Commissioned < 1842