I found and old newspaper clipping about the commissioning if the Stephens Island Lighthouse. Here it is for you to read.
There have been just completed and fitted up at the Milton Works of Messrs James Milne and Son (Limited), Edinburgh, the optical apparatus and machinery for the latest addition to
the scheme of lighthouses which some years ago the Messrs Stevenson, civil engineers, matured for lighting the coast lines of New Zealand. Already, in accordance with the Messrs Stevenson's scheme, no fewer than 27 lighthouses have been erected on salient points of the coast line (which extends to about 3000 miles), and all of them are equipped with optical apparatus in which the latest improvements are embodied. Paraffin has also been adopted at the source of light in the lamps, resulting not only in diminished expense , but in increased power of lights. The apparatus, which has just been completed, is for a lighthouse as Stephens Island, which lies off the North end of the Middle Island, in Cooks Strait, and rises to a height of 950 ft. The lowest site that could be found for the light is about 570 ft above the level of the sea, and if the height of the tower be added, the centre of the light will be about 600 feet above sea level – an elevation which is exceeded by only one lighthouse in Great Britain, Barra Head – which will give a range of 32½ nautical miles for the light. The apparatus is novel in design, and forms a four sided cage of glass, fitted in gunmetal framing, about 8½ feet in height and 6 feet in diameter. Each of the four faces of the instrument is built of two central lenses or discs surrounded by light prismatic rings, with four reflecting prisms below and a crown of thirteen holophotal prisms above. In the focus of the apparatus is a lamp having a burner with five concentric wicks, the flame being 4½ inches in diameter, and possessing a power equal to 515 standard candles. The whole apparatus is made to revolve on a carriage working on steel rollers, which circulate between two rings of steel, the motion being given by clockwork actuated by a falling weight. The machine has a maintaining power which keeps the apparatus going at the required speed even when the weight is being wound up, and provision is also made for working the machine by hand if any accident happens to the winding gear. The apparatus is so arranged that as each face comes into view the observer sees two flashes of intensely white light following each other in rapid succession every half-minute. The lantern in which this apparatus is to be placed is now on the way to New Zealand. It is 12ft in diameter and 9ft in height; The astragals are of gunmetal, and arranged in a series of triangles, thus securing a sruucture of great rigidity and strength; the dome is double, of copper plates riveted together. the triangular panes being of the best mirror plate glass, a quarter of an inch in thickness; and are called “storm panes” are provided, and kept in readiness to be applied in the event of a pane being broken either by birds driving up against the lantern or by stones thrown up from the cliff on which the lighthouse is placed. The lantern was made by Messrs Dove, Greenside Lane, Edinburgh; the optical apparatus by Messrs Barbier, Paris; and the revolving carriage, machine, and lamps by Messrs James Milne and Son. - the whole being
constructed to the designs and under the direction of Messrs Stevenson.
Scotsman, November 22, 1892