An Expert Opinion. The Hieroglyph Read. "Fear no more this lightning flash" (Anon).

Progress, Volume III, Issue 11, 1 September 1908, Page 386

An Expert Opinion. The Hieroglyph Read. " Fear no more this lightning flash " (Anon).

With reference to this subject Dr. Kennedy writes to us (in courteous compliance with our request) thus: — "I have examined the two photographs taken by Mr Duncan from Wellington Terrace on the night of July 24th, but in order to form a definite opinion 1 should know some details concerning the exposure, viz., whether the camera was fixed or moving, and how long the exposure lasted. Judging from the appearance of the photographs. I am inclined to think that they are pictures of part of Wellington illuminated by lightning, together with the trails of the images produced by the electric lamps of the city in a moving camera. Apparently the camera was held in the hand with the lens uncovered waiting for the lighting flash to snapshot itself, as it were. The flash seems to have been bright enough to light up the city for an instant, sufficiently for a snapshot photograph; but during the interval that the camera was held in the hand waiting for the flash of lighting, the electric lights in the city have left trails of light upon the plate. At first sight the trails might appear to be an extraordinary case of multiple and beaded or pead lightning, but in my opinion they are simply due to the elec-

trie lamps of the city. My reasons for thinking so are: — (l)The existence of dotted or beaded lines on the photographs, which are exactly similar to the trails made on a plate in a moving camera by electric lamps that are fed by an alternating current, and I understand that in Wellington the electric lights are on the alternating current system. Lamps fed

by a continuous current give continuous trails on a photographic plate exposed in a camera which is kept in motion, whereas lamps fed by an alternating current give dotted trails when the camera is moved rapidly. The dotted lines in the photographs might have been caused in this way, (2) The trails are too low down to be caused by a lightning flash. Ido not think the lightning flash appears in the photographs at all. I have seen photographs of remarkable multiple lightning flashes taken with a moving camera, some showing as many as forty different discharges in one flash, and I have also seen photographs of so-called beaded lightning, which appears to be due to the incandescence of the air particles along the path of the lightning flash, but I do not think the photographs of Mr. Duncan are examples of either. A simple experiment will prove the truth or error of my explanation. Let a photographic plate be exposed at the same place and in the same way as those from which these prints have been taken, on a dark night when there is no lightning, and I feel confident that the result will be a number of trails caused by the electric lights of the city, similar to those on Mr. Duncans photographs — Yours, etc., D. KENNEDY.

Great Britain has more doctors, proportionately speaking, than any other country in Europe. To eveiy 100,000 persons Great Britain has 150 medical men, Germany 48, Switzerland 42 and Russia 15.