Early 19th century; earliest use found in Michael Faraday (1791–1867), natural philosopher, scientific adviser, and Sandemanian. From electro- + magnetical.
Definition of electromagnetical in US English:
electromagnetical
adjectiveɪˌlɛktrə(ʊ)maɡˈnɛtɪkl
Physics
Electromagnetic.
Origin
Early 19th century; earliest use found in Michael Faraday (1791–1867), natural philosopher, scientific adviser, and Sandemanian. From electro- + magnetical.