"BLINKY BILL"

Dominion, Volume 11, Issue 82, 31 December 1917, Page 6

"BLINKY BILL"

A WINKING EYE OF NIGHT AT THE SHIPS THAT PASS

(By "Sylvius.")

'As soon as the last faint pulse of quivering day has ceased to beat, "Blinky Bill" flashes his glad eye at all and sundry, fair night or foul. He winks just as cheerfully on a clear starlight evening as ho does when the wind howls, the waves leap, and tho rain descends. In confidence, "Blinky Bill" is thought a good deal of by seafarers. He is, as a matter of fact, a guiding light in tho entrance to Port Nicholson, and incidentally one of the most wonderful ideas in coastal lights ever invented. . There were plenty of good lights m the world for tho guidance of ships, but their operation generally is a matter of simple mechanics which have the attention of a keeper or two But in tho case of "Blinky Bill" and the numerous members of his family, very little attention is necessary, and that only once in ten or twelve weeks, according to the capacity of the gas cylinders. "Blinky," who plays his part in the fairway of the entrance to'the harbour, not so very far from the Pinnacles (off Seatoun). is one of the famous Swedish "Aga" lights, invented by one Delen, and is a great labour-saver compared with the ordinary light -n stalled within a lighthouse, and considerably more economical than the ml-burmng beacon, which necessarily nas U i bo kept burning night and day Induced to figures, the "Aga" light effects a savin" of 40 per cent, compared flitna light which has to be. kept going night and day evenly. The wonderful point about "Blinky" is that he turns his'own light on and off. * ****,!* has puzzled many sea-siders, and led tho way to many arguments. How is it possible for a lamp to turn itself on just when its ligW » required and oft when it is not? That is precisely what Delen discovered by delicate mechanical adjustments, tho principles of which are fa'irlv well known to every student of light"and heat The "Aga' light depends for its action on a sun value actuated bv light and not affected by changes of "temperature, but bearing in mind that physically absorbed light acts as heat in contractm* mid expanding metals. In the case of "Blmky the desired effect is gained by a system of metal rods—a central rod surrounded by others equi-distant from each other. Tho great and necessary difference between the rods is that whilst tho central rod is kept blackened with lamp black (in order that it may absorb tho maximum amount of light), the others are kept brightly polished, and are, consequently, light-reflecting. It naturally follows that arl the rods do not expand or contract to the same degree of heat (or light). Tho inner (Mfeck) rod, with its additional expansion, is the first to expand, and by doing so actuates a delicately-construct-ed little valve, the action of which is multiplied by levers into an appreciable movement, and that movement closes the valve and cuts off the supply of gas from the cylinder. Similarly its speedier contraction releases the valve (in the lading of the light), allows the gas free egress to tho burner, which is in contact with a perpetually burning pilot light. Simple! Another feature of "Aga" lightknow to sea-siders as "Blinky Bill"—is its adaptability to almost any kind of occulting light. This is effected by tho aid of a leather flap in some way, but which wav i-s not very clearly known oven- to the Harbour Board's officials, as the "Aga'' lights are supplied on tho condition that a certain part of the mechanical equipment shall not he openp(] U p_thc seal must not be broken. If it is the company declines to guarantee the perfect working of the lamp. The gas supplied for the lamp is acetylene dissolved in acetone—a preparation, which, curiously enough, the Harbour Board has to obtain from NaI pier. It is supplied in metal cylinders, I which last about ten weeks, and ou being exhausted are at once replaced I with"fresh ones. The burner is similar ' to the one used for acetylene gas, and I v-pssure is applied to get an even supply. The Wellington Harbour Board has two "Agn" hoTins. "''" off Ward Is-i-mkl. and "Blinky Bill," situated in the fairway one mile and 3} cables to tb" smith 'of the Ward Island beacon. "Blinky," all may have gathered. 'is an occulting light. Its wink lasts throe-tenths of a second, and is obscured for seven-tenths of a second, so that it winks exactly sixty times per minute. The light is situated 16 feet above high-watermark and is visible all round. That is li'it the case with the other leading feht to the westward of Ward Island. That light (which stands 55ft. above highwator mark) is also occulting, giving two seconds light and two dark. i>ufc its white light only shows down the fairway. From a point off Point Halswell right round to the north and east until a junction is made with the eastern side of the fairway the light shows red, whilst from the same position off Poilit Halswoll, making a westerly sector round to the western edge of the fairway, no light at all is visible. Mariners' know that when thev get "Blinky" in a line with the Ward Island light they are in the deepest part of the channel, and keeping nn (on entering the harbour) they know on owning <wt the red sector of the Ward Island light that they are safe in shaping a course for the inner harbour. The "placing of these two leading lights in tho fairway has robbed the Somes Island light of its chief usefulness. As far as the safe navigation of tiie port is concerned it could, it is held, be done away with altogether without serious consequences, but it is kept going as a Standby in rase anything should go wrong with the Swedish lights, which up till now have douo their work most competently.