2742
THE NEW ZEALAND GAZETTE.
No. 112

is again received. Third: This process should be repeated
several times in order that an average may be obtained.
The following is an example which will serve to illustrate
the foregoing:—

B | | | | .. | | | | | | | 5th and 6th not received.

B | | | | .. | | | | | | | 6th and 7th not received.

B | | | | .. | | | | | | | 5th and 6th not received.

B | | | | .. | | | | | | | 6th and 7th not received.

Average 4·5. Average 9·5. Average of above gives 6
as the minimum point.

This value can also be obtained from the following for-
mula:—

R₁ = Number of sigs. received after the gap.
R₂ = Number of sigs. received before the gap.
N = (17 — R₁) + R₂
————————
2

In the above example—
R₁ = 9·5 and R₂ = 4·5.
N = (17 — 9·5) + 4·5 = 7·5 + 4·5 = 12 = 6....
———————————— ——————— —
2 2 2

Therefore 6 sigs. is equivalent to the sixth point from
north in an easterly direction, or N. 67° 30′ E. Attention
is called to the fact that two bearings, differing by 180°, are
obtained from these readings. One of these bearings is
imaginary. However, owing to the geographical location of
this station, little difficulty should be experienced in separat-
ing the true from the false reading, as the false usually shows
a position inland. Owing to the limited power employed,
the sigs. should not be expected at a dist. exceeding 30 miles.
It is urgently requested that all vessels making use of this
station forward a report of results obtained to the Hydro-
graphic Office in order that any large errors of the set may
be corrected.

Approx. position of station: 40° 37′ 42″ N., 73° 13′ 8″ W.
April.

BRAZIL.

EAST COAST.—NEGRA POINT LIGHT.—CHARACTERISTIC
IRREGULAR.

The first officer of a Norwegian steamer reports that on the
night of 27th March, 1917, Negra Point light was observed
to be showing 1 group of 2 flashes every 10 seconds—thus,
flash 0·5 second, eclipsed 2·5 seconds; flash 0·5 second, eclipsed
6·5 seconds—and not as given in the Light List.

Approx. position: Lat. 22° 57′ 30″ S., long. 42° 40′ W.

RIO DE JANEIRO APPROACH.—RAZA ISLAND LIGHT.—
CHARACTERISTIC IRREGULAR.

The first officer of a Norwegian steamer reports that on the
night of 27th March, 1917, Raza Island light was observed
to show 1 red and 2 white flashes every 6 seconds, and not as
given in the Light List.

Approx. position: Lat. 23° 3′ 40″ S., long. 43° 8′ 45″ W.

RIO DE JANEIRO BAY.—FEITICEIRAS BANK LIGHT
IMPROVED.

On 30th March, 1917, the flashing red light on Feiticeiras
Bank was improved and is now visible 10 miles. The light
is unwatched and shows 1 group of 2 flashes every 6 seconds
—thus, flash 0·3 second, eclipsed 0·9 second; flash 0·3 second,
eclipsed 4·5 seconds.

Approx. position: Lat. 22° 52′ 50″ S., long. 43° 9′ 45″ W.

ARGENTINA.

PLATA RIVER ENTRANCE.—PIEDRAS POINT.—LIGHT
ESTABLISHED.

On 21st April, 1917, a flashing white light every 15 seconds
—thus, flash 0·4 second, eclipsed 14·6 seconds—was established
on Piedras Point.

The light is exhibited 111 ft. above high water from a
square pyramidal iron structure 66 ft. high, with a disk 10 ft.
in diameter placed in a northwest-southeast direction below
the upper platform.

Approx. position: Lat. 35° 26′ 52″ S., long. 57° 8′ 55″ W.

SOUTH AFRICA.

CAPE OF GOOD HOPE.—TABLE BAY.—PROHIBITED
ANCHORAGE.

Position.—Somerset Hospital, lat. 33° 54⅓′ S., long. 18°
25′ E.

Details.—Anchorage is prohibited between two lines drawn
for a distance of 2½ miles respectively, from Somerset Hos-
pital flagstaff, in the following directions: (a) 356° (N. 23° E.
mag.); (b) 346° (N. 13° E. mag.).

Note.—The prohibited anchorage is to be placed on the
charts.

Remarks.—The cable buoy formerly situated about 5 cables
north-eastward of Fort Knuckle has been withdrawn.

Variation.—27° W.

RED SEA, ETC.

RED SEA, GULF OF ADEN, PERSIAN GULF, ARABIAN SEA,
BAY OF BENGAL, AND MALACCA STRAIT.—CAUTION WITH
REGARD TO EXTINCTION OF LIGHTS.

Former Notice.—No. 359 of 1917; hereby cancelled.

1. The lights at the following places have been extin-
   guished: Massawa and approaches (except Shab Shakhs),
   Aden, Jibuti and vicinity (except Ras al Bir), Cape Monze,
   Karachi, Bombay and vicinity, Colombo, Barberyn, Madras,
   Calcutta and Hugli River approaches, Rangoon River ap-
   proaches, Penang, Singapore.

Vessels are prohibited from entering the Port of Massawa
between sunset and 6.0 a.m., and they should not approach
the Port between these hours.

2. All lights in the Persian Gulf and on the coasts of India,
   Ceylon, and the Bay of Bengal are liable to be extinguished
   without notice. Vessels should arrange to arrive at their
   destinations during daylight hours.

Note.—This notice is a republication of the former notice
quoted above, with additional information.

INDIA.

BOMBAY HARBOUR.—APPROACHES.

Vessels engaged in sweeping the approaches to the port
will work in pairs, and will show the following sigs: A black
ball at the masthead and a black ball at the yardarm or where
it can best be seen on that side on which it is dangerous for
vessels to pass. No vessel is ever to attempt to pass between
a pair of vessels engaged in sweeping. Vessels engaged in
sweeping and showing the above sigs. are unable to follow
the rule of the road, and therefore all other vessels are to
keep out of the way. May.

JAPAN.

INLAND SEA.—SHIMONOSEKI STRAIT.—EASTERN ENTRANCE.
—NAKANO SU.—LIGHT-BUOY ESTABLISHED.

Nakano Su North light-buoy, red, conical, showing 10 ft.
above the water, a fixed red light, visible 4 miles, has been
established on the northern edge of Nakano Su, 2,840 yards
355° from He Saki Lighthouse.

Approx. position: Lat. 33° 59′ N., long. 131° 1′ 15″ E.

CHINA.

HONG KONG HARBOUR.—LIGHTS EXTINGUISHED.—PORT
CLOSED AT NIGHT.

All lights at Hong Kong are extinguished and the port is
closed at night. No vessels are allowed to enter the harbour
before 7.30 a.m., and any vessel anchoring outside the har-
bour to await daylight will be viewed with suspicion.

HAWAIIAN ISLANDS.

OAHU ISLAND.—HONOLULU HARBOUR.—LIGHTS
EXTINGUISHED.

Until further notice the following lights in Honolulu Har-
bour will be extinguished:—

Honolulu temporary range-light.
Entrance gas-buoy No. 1.
Honolulu Channel buoy-light No. 3.
Honolulu Channel light No. 4.
Honolulu Channel light No. 5.
Honolulu Channel buoy-light No. 6.
Honolulu Channel light No. 7.
Honolulu Channel gas-buoy No. 9.

CLOSED BY NIGHT.

Mariners are hereby warned that Honolulu Harbour is
closed from sunset to sunrise, and all lights are extinguished.
24th April, 1917.

1. A F. red lt., elev. 60 ft., R. 5 miles, is exh. from a red
   frame lt.-h., in 21° 18⅓′ N., 157° 52′ W., on Stevenson’s
   wharf, 5 cables 145 yds. 22° (N. 12° E. mag.) from Honolulu
   Lt.-h. near the ern. end of Sand Isl. This lt., which is knwon
   as Honolulu temp. leading-lt., when in line with Honolulu lt.,
   22° (N. 12° E. mag.), marks the centre of the outer reach of
   the entr. chan. 2. The F. red lt. on coal-shed at end of