Aurora and electricity. Sir John Franklin’s experience with electrometer.
Sir John Franklin failed to get indications of electricity connected with the Aurora with a pith-ball electrometer; but with another form of electrometer specially constructed for the purpose he seems to have got some, though not very strong or regular, indications of repulsion between the needle of the instrument and the conductor when Auroræ were seen. He does not decide whether the electricity was received from or summoned into action by the Aurora.
Parry’s experience.
Parry, at Fort Bowen, with a gold leaf electroscope connected with a chain attached by glass rods to the skysail mast-head, 115 feet above sea-level, found no effect.
Dr. Allnatt’s experience, February 4, 1872.
Dr. Allnatt, at Frant, during the display of 4th February, 1872, found the earth’s electricity so powerful that the gold leaves of the electrometer remained divergent for a considerable time.
M’Clintock found electroscope affected in Baffin’s Bay and Port Kennedy.
M’Clintock observes that on six occasions of Aurora in Baffin’s Bay, the electroscope was strongly affected, and on three occasions of Aurora at Port Kennedy. The electricity was always positive.
Dec. 18.—Dr. Walker called him to see the electroscope. The charge was at first weak, but afterwards strong enough to keep the leaves diverged. Dr. Walker found two periods of minimum electrical disturbance about 9 P.M. and noon.
Electric currents in telegraphic wires during Auroræ.