Magic Missile Cannon (3.5e Equipment)
From D&D Wiki
Magic Missile Cannon: This item is bulky and heavy, but reigns down mass slaughter via Magic Missiles
It is roughly the size of an 1800's cannon, with five small-ish openings at the front. Towards the back, on top, there is a small, rectangular slot, with two small levers. The Slot is used for the matching cartridge, found in the Wondrous Items section.
One small lever next to the cartridge slot determines the amount of magic missiles fired with each shoot: 1, 3, or 5. The other, obviously, fires the cannon. Operating either lever, or changing the angle is a full-round action that provokes attacks of opportunity.
Space: 5ft by 10ft; Range: 75' long cone;
This item is perfect for D&D Warfare, especially if you do not want primitive gunpowder in your campaign. It could also be found on the tops of watchtowers and on ships (and airships, if those are in your campaign), as an alternative to a catapult or ballista.
Faint Evocation;CL 9; Craft Wondrous Item, Magic Missile; Cost 5,000 gp, 400 XP; Weight: 40 lb lb.; Market Price: 10,000 gp