Encyclopaedia Britannica, 11th Edition, "Armour Plates" to "Arundel, Earls of"

A concise yet vivid account traces the birth of armour plating, beginning with Sir William Congreve’s 1805 proposal for an armoured floating mortar battery and the early American experiments of John Stevens. The narrative follows the practical work of the Stevens family, who by 1841 had measured the thickness of wrought‑iron needed to stop contemporary projectiles, and it notes the growing awareness of shell fire’s destructive power, as highlighted by General Paixhans and French designer Dupuy de Lôme.

The entry then moves to the first real test of the concept during the Crimean War, when three French floating batteries engaged the Russian forts at Kinburn in 1855. Their surprising resilience—sustaining heavy fire while emerging virtually unscathed—shifted armour from speculative idea to a pressing military necessity. Listeners will gain a clear picture of how these early trials set the stage for the broader adoption of ironclad protection in naval warfare.