In a dynamo, a split ring commutator changes the coil connections every half turn. As the induced potential difference is about to change direction, the connections are reversed. This means that the ...

MR. KAPP'S book has passed through a somewhat curious development. Originally written in English, it first appeared in German as a translation; subsequently Mr. Kapp revised, and to a large extent ...

Your car needs electricity. You don't have mice striking flint in your engine's combustion chambers, nor do you have kerosene lamps for headlights. You might be able to hire a string quartet to ...