United States Gunboat Petrel

Single screw; length, 176 feet 3 inches; breadth 31 feet; draft, 11 feet 7 inches; displacement, 892 tons; speed, 12 knots. Main battery, four 6-inch, breech loading rifles. Secondary battery, two 3-pounder and one 1-pounder rapid-fire guns, two 37 millimetre Hotchkiss revolving cannon and two Gatlings. Cost, $247,000.