A: London, England, United Kingdom
This Latin edition of Virgil's Opera, edited with notes by Karl Ruaeus, S. J. identifed itself in Latin, on the verso of its title page, as having been printed by steam power by Benjamin Bensley, the son of Thomas Bensley. Benjamin Bensley's father, Thomas Bensley, was one of the original patrons of Friedrich Koenig, and the owner of one of Koenig's first generation printing machines--the first one used to print books rather than newspapers. The edition was probably a widely adopted textbook at the time, since its imprint indicates that it was distributed by more than ten London publishers, including Longman. Though Bensley may have used the press to print other books between the time of its installation and 1822, this was the first book to unambiguously indicate (in Latin) that it was printed by steam power. It is possible that Bensley added the notation just for the fun of it.
During the Roman Empire, through the Middle Ages and to modern times Virgil's works been a required texts for students of Latin. In 1822 Latin remained a required subject in the academic schools, this edition being very extensively annotated. Notably on the verso of the title page of this edition, in the lower left corner was printed:
Vaporante Machina excudebat
Bolt Court, Fleet Street"
This was also probably the first time that "printed by steam power" was translated into Latin and printed in a book.