Petty’s Measured Conquest
The Down Survey was the year’s most durable Irish development. Directed by Sir William Petty, physician, administrator and practical innovator, it had been undertaken from 1656 and was completed in 1658. It was a vast exercise in measuring land on maps rather than merely describing it in written schedules: the first detailed survey carried out on a national scale. Its immediate purpose was not neutral knowledge. It identified land available after forfeiture so that the Commonwealth could meet commitments to Merchant Adventurers, who had financed the war, and to soldiers owed arrears of pay.