Crossword-Solution: BALLISTAE 9 letters, 1 clue 🏆 scrabble score: 11

The engine: The machines for casting stones, which in Chaucer time served the purpose of great artillery; they were called “mangonells,” “springolds,” &c.; and resembled in construction the “ballistae” and “catapultae” of the ancients.

And so with Marcus Aurelius, Publius Minidius, and Gnaeus Cornelius, I was ready to supply and repair ballistae, scorpiones, and other artillery, and I have received rewards for good service with them.

Music, also, the architect ought to understand so that he may have knowledge of the canonical and mathematical theory, and besides be able to tune ballistae, catapultae, and scorpiones to the proper key.

The difference between "machines" and "engines" is obviously this, that machines need more workmen and greater power to make them take effect, as for instance ballistae and the beams of presses.

With regard to scorpiones, catapults, and ballistae, likewise with regard to tortoises and towers, I have set forth, as seemed to me especially appropriate, both by whom they were invented and in what manner they should be constructed.