But no strictly electromagnetic apparatus for telegraphic signalling was put to successful use until 1836, when, in England, Charles Wheatstone, who is commonly regarded as the first inventor of practical electric telegraphy, constructed an apparatus whereby thirty signals were transmitted through nearly four miles of wire.

Devoting every spare moment to the pursuit of his object, which was attained but slowly by reason of his lack of mechanical skill and ingenuity, not until 1837 had he so far succeeded in his efforts as to be prepared to make application for letters-patent to enable him to secure and protect his rights of invention in the electromagnetic telegraph.

[electromagnetic object] quadrupole.

I'm going to create the biggest electromagnetic pulse this Solar System has ever seen, and BURN every last one of those probes out of the void!!

As the power system aboard that same asteroid screeched into disruption and then silence, a massive electromagnetic shock wave was dispensed from its surface.

Then he suddenly initiated the electromagnetic pulse to fry the microwave probes, but he also fried his own system.

Electromagnetic theory.

Leo C. Rosten (A); 30Jan69; R454229. ROTERS, HERBERT C. Electromagnetic devices.

SCHELKUNOFF, S. A. Electromagnetic waves.

KING, RONOLD W. P. Electromagnetic engineering.

Electromagnetic theory.

Leo C. Rosten (A); 30Jan69; R454229. ROTERS, HERBERT C. Electromagnetic devices.

SCHELKUNOFF, S. A. Electromagnetic waves.

KING, RONOLD W. P. Electromagnetic engineering.

We vibrate in sympathy with a few strings here and therewith the tiny X-rays, actinic rays, light waves, heat waves, and the huge electromagnetic waves of Hertz and Marconi; but there are great spaces, numberless radiations, to which we are stone deaf.