Short answers, pulled from the story.
A barque is a sailing vessel with three or more masts in which every mast except the aftermost carries square sails, while the aftermost mast (the mizzen in a three-masted barque) is rigged fore-and-aft. Barques were common ocean-going vessels during the golden age of sail in the mid-19th century because they could be operated with smaller, cheaper crews than fully square-rigged ships while achieving nearly comparable speeds.
The modern convention is that barque (with a q) refers to a ship, while bark refers to a sound or tree hide. In Britain, the spelling settled into the French form barque by the mid-19th century. Francis Bacon used the q spelling as early as 1592, but Shakespeare still wrote "barke" in Sonnet 116 in 1609.
Barque entered English through French, which took it from the Latin barca. Latin may have received it from Celtic barc (per Thurneysen) or from the Greek baris, a term for an Egyptian boat, though the Oxford English Dictionary considers the Greek origin improbable. The Celtic barc form is also considered an early source, possibly reaching English via Irish.
The Star of India is the oldest active sailing vessel in the world. It was built in 1863 as a full-rigged ship and converted into a barque in 1901.
The USCGC Eagle is an operational barque used as a training vessel by the United States Coast Guard Academy in New London. It was built in Germany in 1936 and captured as a war prize.
In ancient Egypt, barques were central to religious belief, used to transport the dead pharaoh to become a deity and to carry cult statues of gods during festival processions. Temples included barque shrines where sacred vessels rested between ceremonies, watched over by priests. The Milky Way was understood as a celestial waterway for divine barques, analogous to the Nile.