June 24.] THE NEW ZEALAND GAZETTE. 1671

Communication between Vessels at Sea.

Beside their usefulness in warning vessels of their approach to the land and to dangers, submarine sound-signals may be used as a means of communication between vessels at sea. For this purpose the sound-producing bell, immersed in water held in a tank, is installed in the forepeak of the vessel, inside of the hull, and may be operated automatically or by hand. As a means of communication between submarine boats in a state of submergence, this method of signalling has a special field of utility. During the tests of submarine boats in May, 1907, communication was in this manner kept up between the “Octopus” and the tender “Starling.” Signals were communicated from the “Starling” to the “Octopus,” telling when the latter had crossed the finish lines and when to come to the surface, and distinct messages were received in return from the submerged vessel.

The Equipping of Vessels with Submarine Sound-receivers.

The maritime community has availed itself more and more of the facilities which have thus been provided by the fostering care of the various Governments, with a view of lessening danger in navigation and delay in transportation, and an increasing number of vessels have, year by year, been furnished with submarine sound-receivers, and, for the convenience of underwriters in determining rates of insurance, the American Bureau of Shipping has noted in “The Record of American and Foreign Shipping,” which of the vessels are so equipped. The saving of time brought about by enabling vessels to reach port instead of being delayed by fog and losing tides is being constantly exemplified. The “Lucania,” while approaching New York on one occasion, made all three light-vessels by submarine-bell sounds, which constituted the sole guide: and we read in the Cologne Gazette that the captain of the “Kaiser Wilhelm der Grosse” during the course of a voyage to New York, when surrounded by a dense fog off the coast near Fire Island light-vessel, heard the submarine bell and was able to steer by it, when, as it subsequently transpired, he was twelve nautical miles distant from the signal-station. At 6.45 a.m. the sound of the bell was heard to starboard, and, owing to the fog, the ship, which was some distance out of her position, was guided solely by these bell-signals, and the course was altered by the sounds heard from the light-ship, though the fog-horn was wholly inaudible.

The Range of Audibility of Submarine Bells.

While careful listening at the telephone is always a requirement that must not be underrated nor overlooked, it is found that vessels of deep immersion have an advantage in the range of distance at which submarine sound-signals may be detected, and this is accentuated in cases where they are moving at a slow rate of speed. Indeed, on the Great Lakes, where the forepeaks of vessels are frequently above the water-line, special provision was necessary for the proper submergence of the tanks containing the sound-receivers. There appears to be no failure to hear and recognise the sounds of the submarine signal-bells at distances between three and five miles, and on the average these distances are considerably exceeded. What range of submarine transmission of sound-waves will ultimately be set as the limit of practical audibility of such signal-bells is not now known, but the possibility of a comparatively extended range, under special conditions, is foreshadowed in the observations that have been lately made between the light-vessel “Gabelsflasch,” located at the entrance to Kiel, Germany, and the light-vessel “Fehmarnbelt,” situated nearly twenty-seven nautical miles away. On different occasions the ringing of the submarine bell on the latter light-vessel was heard by the unaided ear through the naked walls of the carpenter’s store-room on the “Gabelsflasch” vessel. Without doubt this remarkable transmission was favoured by the form of the sea-bottom, which, while not of an even depth in the region between the light-vessels, does not suffer any sudden or great irregularities; and, perhaps, the energy of the sound-waves, freed of interference by the infrequency of traffic in midwinter and by the absence of agitation of the waters from storm, was conserved and strengthened by the narrowing shape of the borders of this portion of the German Sea. Although there are some situations in which the submarine sound-signals are cut off, as, for example, when an underwater formation, like a bank or shoal, rises from the bottom and culminates near the surface of the sea, these observations on the “Gabelsflasch” vessel indicate that conditions may be found or arranged which will be exceptionally favourable for the distant transmission of signals. Thus, where there is a funnel-shaped entrance bounded by jetties running far out into the sea, it may be practicable, by the concentration of waves from an origin of sound placed near the vertex of the funnel, to mark out a sharply defined sound-sector for the purpose of locating the entrance when it is obscured from view by fog or darkness.

Notice to Mariners No. 44 of 1909.

Marine Department,
Wellington, 16th June, 1909.

THE following Notices to Mariners, received from the Port Officer, Melbourne, are published for general information.

J. A. MILLAR.

VICTORIA.
Port of Geelong.

On and after 4th May, 1909, a fixed green light will be exhibited from the outer end of North Geelong Pier (North Geelong), visible 1½ miles in clear weather.

GEO. A. MOLLAND,
Harbourmaster.

Geelong, 3rd May, 1909.

Warrnambool Harbour.—Visibility of Upper Lighthouse.

Referring to General Notice to Mariners dated 1st August, 1907, page 52, relative to directions for entering the harbour, it is hereby notified that, as the upper or rear lighthouse cannot be plainly seen when entering about noon, the water-tower, open its own width to the westward of the lower lighthouse, may be taken as being in line with the higher lighthouse (until it is visible). Such water-tower is round with a flat top, visible high above the trees and land, therefore it is easily distinguished from other adjacent towers and spires, and is specially useful when used as a mark in the way described, when the sun is near the zenith.

C. W. MACLEAN,
Port Officer.

Melbourne, 19th May, 1909.

Notice to Mariners No. 45 of 1909.

LEADING-LIGHTS FOR NEW ENTRANCE TO NELSON HARBOUR.

Marine Department,
Wellington, N.Z., 21st June, 1909.

THE Nelson Harbour Board notify that the following leading-lights have been established to lead through the new entrance:—

1. First Reach.—Front light fixed red, exhibited from a white beacon in 41° 16′ S., 173° 17′ E., 1⅓ cables N. 14° E. from the rear beacon for the old channel. Rear light fixed red, exhibited from a white beacon 37 yards S. 63° E. from the front beacon. These beacons in line S. 63° E. lead through the entrance to new channel between the breakwaters. The position of these beacons is liable to alteration to meet the changes in the channel.
2. Second Reach.—Front light fixed white, exhibited from a flagstaff on pier at Pilot’s boatshed. Rear light fixed white, exhibited from a post 70 yards N. 88° E. from the front light. These beacons in line N. 88° E. lead from their intersection with the first leading-line into the haven. These lights are to be replaced by permanent lights in another position when the works are completed. A fixed green light is exhibited from the outer extremity of the wharf next southward of Government wharf. A bank is forming westward of Boulder Bank and southward of the fairway buoy.
   Charts, &c., affected: Admiralty Charts Nos. 2616 and 2185; “New Zealand Pilot,” eighth edition, 1908, Chap. vi, page 188; “New Zealand Nautical Almanac,” pages 166 and 297.

J. A. MILLAR.

Notice fixing Closing-hours of Tobacconists’ Shops in the Borough of Petone under the Shops and Offices Act.

WHEREAS a requisition in writing, signed by a majority of the occupiers of all the tobacconists’ shops in the Borough of Petone, has been forwarded to me, desiring that all such shops within the borough shall be closed at 8.30 o’clock p.m. every day, except on Wednesdays and Saturdays, when the hour shall be at 1 o’clock p.m. on Wednesdays (the weekly half-holiday), and at 10.30 p.m. on Saturdays; except on the night before New Year’s Day, Anniversary Day, Picnic Day, Good Friday, Prince of Wales’s Birthday, Labour Day, King’s Birthday, Christmas Day, when the hour of closing shall be 10 o’clock p.m.: And whereas the Petone Borough Council has certified that the signatures to such requisition represent a majority of all the tobacconists doing business within the borough :