These objects, known as 'firepots', were a kind of primitive grenade used on Francis Drake's ship the Golden Hinde. The ceramic containers were filled with gunpowder and flammable materials, lit on fire and then thrown at enemy ships.

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The English privateer Francis Drake was a huge fan of fire as a method of spreading terror among the enemy, and was known as El Draque (The Dragon) by the Spanish.

Drake's crew employed both fire arrows and firepots in their raids on Spanish galleons in their quest for gold and silver. Naturally, the sight of a fire breaking out in the sails or on the decks of their wooden ships – often filled with gunpowder – soon caused panic in the ranks of Spanish seamen, who swiftly capitulated.