Howitzer

 are generic units available in the Industrial Era, after researching the Military Coordination technology.

Class and Specialty

 * Ranged-combat Unit, must have line of sight to attack. Can destroy fortified tiles but cannot retaliate when attacked by a close-combat Unit.
 * Ranged-combat Unit, must have line of sight to attack. Can destroy fortified tiles but cannot retaliate when attacked by a close-combat Unit.

Upgrades from
Upgrade cost and needs,  access on empire.
 * Mortar (generic)