LIGHTHOUSES AROUND THE NEW ZEALAND COAST.

Manawatu Herald, Volume LI, Issue 4528, 8 November 1930, Page 4

LIGHTHOUSES AROUND THE NEW ZEALAND COAST.

INTERESTING' ADDRESS BY

MR. J. A. SMITH.

Mr. J. A. Smith, of Levin, the speaker at Thursday’s meeting of the Foxton Luneii Club, gave a very interesting address to member's on “Lighthouses Around the New Zealand Coast.”

Mr. W. Trueman introduced the speaker, whom he said had spent several years at sea and had obtained a first-hand knowledge of lighthouses around the New Zealand coast and their operation. Mr. Smith said that 1m had recently listened to an address at the local Lunch Club by Mr. Cr. A. Monk on “Main Highways.” His subject really concerned the highways of the sea but there was a vast difference between the lighting of the former and latter. In lighting a. main highway as much carp as possible was taken to throw the light on the road, but at sea things were different, for instead of the light being concentrated on •the ocean it was so arranged to ‘■shine in a particular direction so that the candle power of the lamp was used to the best advantage, seen the furthest distance and penetrated haziness and fog. There were in all 183 lights around the 'New Zealand coast including the leadiing lights and buoys in the main harbours. They comprised several types, the most common being the ordinary lighthouse with which everyone was more or less acquainted. There were 27 of these, including the Moko Hinou, situated 14 miles north-west of the Great Barrier and Cape Brett, photos of which Mr Smith handed round. This type of lighthouse was in charge of either two or three keepers and the source of illumination ay as from vaporised kerosene, the lamp containing a burner and mantle into which the gas was forced by a pump which operated on the lines of the ordinary kerosene primus. These lamps were on continuously and did not hash in the technical sense. They revolved, however, and sent out shafts of light-like beams from a number of spot lights which had the appearance from the sea of hashing, but if the observer watched carefully he would see the light come in and then fade out. All lights around the coast hashed at different intervals and by this means a. ship making the coast of New Zealand or proceeding along the coast in dirty weather was able to ascertain its position as all the officer on watch had to do was to note the intervals of hash and refer to chart to know exactly where he was.

'The highest lighthouse on the New Zealand coast, said Mr. Smith, was on Stephens Island where it was 600 feet above sea level. The beam from this lamp could he seen 32 miles out at sea on a clear night. Cape Brett light was 510 ft. above sea level and could he seen 30 miles out to sea, the East Cape light 505 ft. and discernible a similar distance, the Moko Hinou 385 ft. and Cape Maria 330 ft. The lowest lighthouse in these parts was the one at Cape Farewell which was constructed on the sand and the base of the tower was only between six and eight feet above high spring tide while the lamp was hut 07 feet above sea level and could be seen only 15 miles away. Besides the ordinary keeper lighthouses, there were four automatic lights in operation, which owing to the fact that they were situated in dangerous localities were kept under constant observation in order that, any interruption of the light might be attended to immediately. These lamps were operated by means of sun valves which lit and extinguished the lamps at the end and beginning of the day independent of the time of the year. They were 'about ten feet high and constructed of boiler plating and contained four cylinders of acetylene gas. A small pilot light >vas burning all the time and when the gas was turned on at the close of the day the lamp lit up. ■Until a method of compressing acetylene gas was discovered, said Mr. Smith, tliese lights had not come into operation. The compression of acetylene was 'a highly dangerous business until two French chemists named Claude;and Hess discovered that liquid acetone absorbed acetylene up to 25 times the volume for every atmospheric pressure. Acetylene gas was then pumped into acetone. The cylinders were not quite filled.. however as the acetone expanded four per cent, for every atmospheric pressure. As the containers had to he handled very often under trying and awkward conditions in the lighthouse work around tliis coast kapoc or some other material was inserted in the cylinders to stop the liquid from swishing about. The kapoc swelled out arid prevented any movement of the liquid making it thus safer to handle by reason that it did not allow any space for gas.

'There were two makes of automatic light in operation in iNgw Zealand waters, one of iEnglish malice and the other of Swedish construction, the latter ibeing used extensively along the coast of Sweden. The gas from 'the cylinders entered a chamber at ithe bottom of the light at 1301 b. pressure, but as the pressure required at the burner was only small it bad to be reduced before reaching there. A govex-nor controlled this mad delivered the correct pressure to a diaphram which was illustrated by the speaker by means of sketches. The diaphragm was worked by a spring and moved up with the inflow of the gas from the cyliuder and down as it expelled the gas into the burner operating valves which opened and shut regulating

the supply of gas from (lie cylinder. The pilot light operated it) the same manner as in ordinary lights. The gas was turned on bv means of the sun valve which was operated entirely by light and was in no way affected by a ehange'in temperature. The prinriple on which it worked was based entirely on the fact that absorbed light was transformed into heat. Two types of sun valves were demonstrated and explained by Mr. Smith. One consisted of two glass bowls connected together by a small glass tube and filled with liquid ether. This was hung on a centre pin and the ether could move freely from one bowl to another and see-saw and operated a little lover which in turn operated the gas cylinder. One howl was painted with lamp black and absorbed the light. As soon as it was sufficiently light this howl, by absorbing light rays which developed heat, transformed some of the ether into gas which pushed down the other and upset the balance by causing the other bowl to tip and operate the lever shutting off the gas. The opposite happened in the evening with the approach of dusk and the gas was turned on again. The other type consisted of three metal, pillars, two polished and one black, the expansion of the one operating a lever in a similar manner. The movement necessary was only about a sixty-fourth of an inch as the whole mechanism was of a very delicate nature. When shore parties visited the an-' tomatie lights, a special cover was placed over the sun valve in order to set the lamp iii operation to see that everything was in perfect working order. All automatic lights (lashed, said the speaker, but at varying intervals. There might be a second of light and a short interval of darkness the first time and the next time the interval of darkness might be longer and so on and this was controlled by a trip mechanism which altered the Consumption of gas blown into the burner. The lamp itself was protected from insects and birds and the lens were so arranged as to concentrate the light into a beam. The lenses were constructed like prisms to make the best use of the light and throw a flat beam the whole wav round which could be seen equally as well from sea level as from the mast head of the biggest ship likely to (visit the locality. These automatic lights were attended to once in four months by the lighthouse fender. Mr. (Smith submitted a photograph of Cables End lighthouse north of Gisborne, in which it appeared as it Cables End had at some time slipped from the mainland. A dangerous channel divided the island from the mainland and the light was situated on the island. To roach it the landing party had to moor their boat to a rock in the channel and jump ashore on to a platform. They then proceeded to the top of the hill and let down the empty cylinders by a hand windlass and hauled lip the full ones, a very difficult and dangerous business at the best of times.

Harbour lights, said the speaker, were controlled by the various Harbour Boards, but the Marine Department looked after the remainder and the old Tntanelkai had carried out this work - for many years. This vessel had now been replaced by the Matai which was on its maiden voyage at present under the command of Captain 1 Burgess, who bad been in charge of the service since the late Capt. (Hollands passed away and with whom Mr Smith had served. ICapt. Burgess held a very responsible position and hacl to take his ship into all sorts of plaices and anchor in many precarious anchorages during the course of his inspection of the various lighthouses of this coast. The Wellington Harbour Board had recently installed a new light, which contained an interesting mechanism. It was operated by acetylene as the others wore but it was a mantle lamp and a mechanism was so 'arranged that when a mantle broke and the lamp Hared up it set the mechanism in operation and another mantle moved round and dropped into position on the standard. A shelf containing spare mantles was provided and the

whole business was carried out automatically. In conclusion Mr Smith said that ho did not think that many more big lighthouses would he constructed. The day of the radio beacon was at hand and these would replace the ordinary lighthouses. They would undoubtedly have to retain tho present ones in- use

around the New Zealand coast for ■some time yet, but the radio beacon was far better as it enabled ships with wireless to obtain their bearings much more easily. Mr. Smith was accorded a hearty vote of thanks for his interesting address on the motion of Messrs \V. E. Bullard and Li. J. Thompson mil at the conclusion of the meeting was persuaded to deliver the address to the secondary department of the local District High School, where he spoke to an equally interested audience.