@Cycloptichorn,
Yeah, but i was talking about
scale. You can build Da Vinci's tank, for example, in a scale model, and it's just hunnky-dory. But try building it to a size which would accomodate men and horses, and it's too heavy to work, and so heavy it would destroy itself.
I didn't see the one about rockets--i don't watch it any longer. But as for rockets in the 19th century, they must not have done their research. The Brits fought the Indians of Mysore in the early 19th century, and the Indians used rockets against them. So some joker named Congreve in England worked on the design, and the Brits used Congreve rockets by land and by sea for quite a while thereafter, beginning with the Second Coalition war with Napoleon. They fell into disuse, though, as infantry weapons got more accurate at longer ranges, and the nickel finally dropped for the opponents of Napoleon and they began making and using more effective field artillery. But rockets in the 19th century? That ought to have been a no brainer.