His father, George Ewing, settled at Lancaster, Fairfield county, Ohio, in 1792.
Another son, Thomas Ewing (1829-1896), studied at Brown University in1852-1854(in 1894, by a special vote, he was placed on the list of graduates in the class of 1856); he was a lawyer and a freestate politician in Kansas in 1857-1861, and was the first chiefjustice of the Kansas supreme court (1861-1862).
This last method of arrangement is called by Ewing the " one-pole method, because the magnetometer deflection is mainly caused by the upper pole of the rod (Magnetic Induction, p. 40).
A plan of the apparatus as arranged by Ewing for the latter purpose is shown diagrammatically in fig.
The effect of the ends of the wire is, as Ewing remarks, to shear the diagram in the horizontal direction through the angle which the sloping line makes with the vertical.
