Electrical Discharge—Possible Cause of Flare Spots in Photographs

Abstract

DURING a recent yachting cruise on the north-east coast, I sailed from Holy Island to St. Abbs, arriving off the harbour before the fishing fleet came out, and therefore dropped anchor off the entrance. About 5.30 p.m. some of the Scotch herring boats sailed out, and I photographed one shortly after leaving the entrance, and another when she was well outside. On having the two negatives developed and printed, I was disappointed to notice that both pictures were considerably marred by a white flare extending from the mast and yard of the sail skywards. At first I put down the flare spot to light leaking into the camera, or some sort of optical halation. On considering the matter more carefully, I was struck with the coincidence of both photographs showing the defect starting from the yard and the mast, and not at all visible on the lower dark sail. I talked the matter over with several friends, and eventually Mr. C. Faraday Proctor jokingly suggested it was evidently caused by electrical discharge. We both took the idea in a sarcastic spirit; but very soon we realised that the suggestion was not so ridiculous, and was well worthy of serious consideration, particularly as I remembered that the weather conditions had been thundery during the two previous days whilst sailing up from Blyth to Holy Island. I then carefully examined other photographs taken on the following day of boats in the harbour, and several of these showed evidence of the same effect.