A PHENOMENON EXPLAINED.

Evening Star, Issue 3730, 5 February 1875, Page 3

A PHENOMENON EXPLAINED.

To the Editor, Sib,—The phenomenon related by the Rev. J. Williams aud reported in your issue of Wednesday is capable of the following explanation : When a body charged with positive or negative electricity is brought into relationship with a body oppositely charged, a chemical combination of the two electricities results, producing, if the union be sudden and intense, a flash of light and noise (lightning and thunder), but if the union be gradual and feeble a continuous flame is produced, this flame being called by writers on meteorology St, Elmo’s Eire. One of these Mr A* Buchan, secretary of the Scottish Meteorological Society, says “ the finest aud most beautiful displays ot this most striking phenomenon occur at sea during storms, when it appears as alight resting on the masts. Mr William Trail, of Auckland, gives a particular description of it as seen by him there during a storm in 1537. The mast was illuminated, and from the iron spice at the top a flame a foot in length pointed to a dense cloud rapidly advancing from N.N.W. As the cloud, accompanied with thunder and bail, approached, the flame increased, following’ the course of the cloud, till it reached three feet in length, when the cloud was passing overhead ; after which it quickly diminished, but continued to point to the cloud as it was borne to the R.S. E. It lasted about four minutes, ff in a dark room we bring a needle close to the conductor of an electric machine when charged, a light will be seen to play on the point of the needle, caused by the combination of the electricity of the conductor and that of the needle, which is charged by induction with the opposite electricity to that of the conductor. This simple experiment explains St. Elmo’s Fire.”— I am, &c., _ Geo. W. Cole. Dunedin, February 5,