The art of binding elementals is a craft mastered so far only by the gnomes of Khorvaire. Elementals are bound so that their energies may be used to power the device to which they are connected. Khyber shards are commonly used in elemental binding magics. Elemental-powered airships and the lightning rail are the most common examples of elemental binding, but they can be bound to weapons and armor as well as less militial devices.
The Orien [lightning rail]] was originally commissioned by the King of Galifar before the Last War. House Orien and House Cannith collaborated in the design and the gnomes of Zilargo provided the power for the vehicle with bound air elementals that propel the coach over a magical conduit of conductor stones. When the stones mounted below the coach pass over the conductor stones lining the ground a sparking or "lightning" effect is produced which accounts for the origin of the name. The lightning rail travels at 30 miles per hour and was a great revolution in travel for the citizens of Khorvaire. However, a significant part of the circuit was destroyed during the Last War and has not yet been repaired, including the rail lines in Metrol and the rest of Cyre, which was destroyed on the Day of Mourning.
The airships of House Lyrandar are a relatively recent invention, first produced toward the end of the Last War in 990 YK. House Lyrandar enlisted the help of the Zilargo gnomes to power their soarwood ships and created the wonderous vehicles that fly over the Five Nations today. Airships use an air elemental or fire elemental bound to a ring between two struts toward the back of the ship, an artificer or bearer of the Mark of Storm is required to force the elemental to bear the ship in the manner desired.
The artificers of House Cannith are working hard to unlock the secrets of gnomish elemental binding, especially Merrix d'Cannith, the baron of Cannith South, who directs Cannith operations in Zilargo from Cannith Tower in Sharn.
Eberron Campaign Setting. Keith Baker, Bill Slavicsek, & James Wyatt (2004). Wizards of the Coast. ISBN 0-7869-3274-0. Magic of Eberron. Bruce R. Cordell, Stephen Schubert, and Chris Thomasson (2005). Wizards of the Coast. ISBN 0-7869-3696-7.