[central_va]

At the turn of the 19th century ships were made out of wood.

[SoCal Pubbie]

I think they are referring to around 1900, when the 19th Century was turning to the 20th.

[Kirkwood]

Iron hull ships were introduced in the late 1780s.

[SunkenCiv]

The writer just messed up a little -- turn of the 19th c is generally 1799 to 1800 (or 1800 to 1801, for those into nitpicking semantics) and clearly he or she is talking about 1899 to 1900 (or 1900 to 1901).