Excellent condition grenade or grenado from the period of the American Revolution and the age of fighting sail. Crudely cast from iron, hollow with a visible seam line and prominent sprue mark, grenades did not need to be well finished to serve their purpose. Taking a wood fuse and filled with powder, they were lit with a piece of slow-match and used both on land and sea. Perhaps the best known occasion of their use in the Revolutionary War was by the sailor on board the Bonnehomme Richard who managed to lob one down a hatchway of the Serapis, setting off a devastating series of explosions and giving John Paul Jones the victory.
On land, grenades were used in the attack and defense of fortifications. Joseph Plumb Martin remembered the British throwing grenades as the Americans stormed Redoubt Number 10 at Yorktown, and another American recalled seeing French grenadiers attacking Redoubt Number 9 with grenades in the same engagement.
There are a number of excavated examples. Gilkerson shows a slightly larger one recovered from the HMS Invincible, sunk in 1757. Early ones have come off pirate vessels as well, both the Whydah Galley and Blackbeard's Queen Anne's Revenge. One of the latter is pictured online and seems to measure about 7.5 cm in diameter, or 3 inche. It makes sense that it was grenades of this smaller size that were carried by grenadiers and carried in budge barrels up into the fighting tops.
There are minor differences in size, but Gilkerson, in his discussion of their use at sea notes they tend to measure 3 to 3 inches in diameter. This one measures approximately 2 inches in diameter, exclusive of seam or sprue mark, weighs 2 pounds and has a fuse hole 5/8 inch in diameter.
This is a top-notch, clean example, showing the just the expected overall pitting and unevenness of a porous iron, but with no rust or scaling. I see an identical example brought $1,200 at an Early American History Auction some time ago. This one is more reasonable.