SAVING THE BIRDS.

Manawatu Herald, Volume XXXVI, Issue 1279, 1 August 1914, Page 4

SAVING THE BIRDS.

Tins electrocution of birds by overhead wires is considered in Germany a mutter of sufficient moment to warrant special precautions being taken to prevent its occurrence. In a French journal, “L’Jilectricien,” some of these precautions are detailed. The causes of this ‘‘massacre of the innocents,” which is proceeding daily in every big city, are tbps analysed(l) Mechanical striking of the flying bird against unnoticed wires; (2) contact with the two wires at different potentials by the bird with outstretched wings; (3) simultaneous contact with an electrically charged wire and another metallic piece connected with the earth. The first of these risks exists in the case of ordinary telegraph wires; but the number of birds that perish by simple mechanical shock against the wires is comparatively negligible. To obviate the second risk, the German Electrotechnical Association has framed between wires at different potentials must be such that the outstretched wings of a bird cannot span them. A special case is where a string of birds, perching on ap electpie wif«, are ip contact, and thbgp at tpe ends then touch two different conductors, The whole lino will then be shocked to death. Such an occurrence, however, is infrequent. The most serious danger threatening birds is in the neighbourhood of tno supporting posts. Here electrocuted birds are found in greatest numbers. This is because the birds are accustomed to perch on the horizontal metal bars carrying the insulators, 3P,4 then to peck at the wire, when the current at ppce passes from line to earth, through the bird's body. It lias been proved, the writer In L ‘Electric! en says that conductors carrying electric energy at a tension above 110,000 vods arc not dangeroustp birds, as in such installations the inipifatprs have to bo so large that birds perched on the supports mpuot reach the wire attached to the top of the insulator. A German electric-supply house has therefore conceived the idea of placing insulators on supports so high that the birds cannot reach the 'conductor, while ijpothor bouse upes cross-pieces inclined at' ah angle of $

degrees so that birds cannot easily perch on. them. To do away with the danger of existing pieces of porcelain resembling the insulators are fixed on the cross-piece near the real insulators. If tho unwary bird perches on the cross-piece lie is too far from the wire to reach it; whereas, if he perches on tho porcelain and pecks the wire, there is no risk, because his feet are insulated.