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mile. A sand cay that bares 4 feet (1.2 m.) at low water lies near its southern end.
The eastern side of the reef is steep-to; however, on the western side for a distance of 112 miles it slopes gradually from 8 to 15 fathoms (14.6 to 27.4 m.), and this vicinity affords an excellent anchorage.
Middle Reef, lying 12 mile southward of Meridian Reef, is 21/2 miles long north and south. A sand cay lies near its northern extremity. The channel between Meridian and Middle Reefs has a depth of 13 fathoms (23.8 m.) in the middle, but is too much narrowed by shoal water running off the reefs on either side to admit of a ship using it with safety, as the currents run through it with great velocity.
Frances Reef, latitude 4°25' N., longitude 119°15' E. (southern end), immediately southward of Middle Reef, is the southernmost of the chain of reefs extending from Andulinang Islet. It is 434 miles in length northeast by north and southwest by south. The eastern side of Frances Reef is quite steep. The western side, on which there is a long sand cay bare at low water, shoals gradually. The channel between Middle and Frances Reefs has 6 to 7 fathoms (11.0 to 12.8 m.) in it, but it is narrow and the edges of the reefs are ill defined. Moreover, it has not been closely examined.
Tidal currents.—On the edge of the bank, southwest of Frances Reef, there are strong tide rips and overfalls. The flood stream runs here with exceptional strength, frequently as much as 3 knots, and sets southward and southeastward over the edge of the bank.
Channel. The channel on the western side of Meridian and Frances Reefs, and eastward of Blake Reef, Payne Rock, and James Patch, is convenient as affording anchorage in every part; the only narrow part of it is when passing Maranas Islet, which may be passed on either side, and no special directions are necessary.
Blake Reef, westward of Maranas Islet, is 234 miles long north and south by 1 mile in width. The channel between Blake and Maranas Reefs is 23 mile wide.
Bulubulu Islet, situated 33/4 miles 207° true from Maranas Islet, is a small, flat island planted with coconut trees, the tops of which are 55 feet (16.8 m.) above the sea. The islet is surrounded by a reef to a distance of from 200 to 400 yards, and a small coral patch of 71/2 fathoms (13.7 m.), lies 3/4 mile 3260 true from it. Another patch, on which there is 6 fathoms (11.0 m.), lies within the 10-fathom (18.3 m.) curve surrounding the islet, and 0.8 mile 195° true from it.
Anchorage may be found eastward of Bulubulu Islet in 13 to 17 fathoms (23.8 to 31.1 m.), sandy bottom.
Payne Rock, awash at low water, is nearly in the center of a narrow shoal of sand and coral, 34 mile long north and south, with depths of 3 to 5 fathoms (5.5 to 9.1 m.) over it, and lies 7 miles south from Bulubulu Islet.
James Patch is a small coral patch with 7 fathoms (12.8 m.) on it and 8 to 20 fathoms (14.6 to 37 m.) around. It lies 314 miles southward of Payne Rock.
Channel.—The channel westward of the line joining Blake Reef and Payne Rock and eastward of Riddells Reef is 27 miles long and 3 miles wide in its narrowest part between Blake Reef and Siluag Islet. It is perhaps the most convenient to use generally, being more direct than those farther eastward, whilst the tidal streams do not attain the same strength as in the channels westward.
Siluag Islet, latitude 4°43' N., longitude 119°09' E., is somewhat larger than the islets noticed above, being 13 mile long north and south, lying 634 miles 244° true from Andulinang Islet. It is flat topped and planted with coconut trees, the tops of which are 70 feet (21.3 m.) above the sea. There is a fringing reef of from 50 to 300 yards in width surrounding this island.
There is a coral shoal 11/2 miles 18° true off Siluag Islet, which has a least depth of 71/2 fathoms (13.7 m.) on it.
Riddells Reef, the north end of which lies 41/2 miles southward of Siluag Islet, is a narrow coral reef, 23/4 miles long, north and south, with two sand cays that bare at low water near its southern end.
Nearly midway, and exactly in the line between Siluag Islet and Riddells Reef, there are two coral shoals; the northern of these has on it a patch of 514 fathoms (9.6 m.) at 21,2 miles south of Siluag Islet, with 15 to 19 fathoms (27.4 to 34.7 m.) over the rest of the bank; the other is 1 mile farther south, or 113 miles from Riddells Reef, and 12 mile in diameter with 234 and 334-fathom (5.0 to 6.9 m.) patches on it.
Channel.—The channel west of Siluag Islet and Riddells Reef and east of Bajapa Reef is 7 miles long, with a minimum breadth of 134 miles. The tidal streams run here with great strength, and they should be well considered before using this route.
Bajapa Reef, the northeastern end of which lies 214 miles westnorthwest from Siluag Islet, is 834 miles long in a north-northeast and south-southwest direction and 112 miles wide in the middle. It bares in patches at half tide and incloses a lagoon in the center, the entrance to which is on the southwest side. This reef is steep-to on all sides, except at the north end, where shoal water extends out for a short distance.
Channel.-The channel between Bajapa Reef and Alice Reef is about 6 miles long and 11/2 miles wide between the steep edges of the reefs on either side. The tidal streams run straight through the channel with considerable strength.
Alice Reef, northward of Bajapa Reef, is 512 miles long northnortheast and south-southwest, with an extreme width of 134 miles in the middle and bares in spots at low water. It is steep-to around, except off the northeast point, from which point the 5-fathom (9.1 m.) depth curve lies at a distance of over 12 mile.
Panguan Islet, latitude 4°43' N., longitude 119° 02' E., is a small wooded islet, 60 feet (18.3 m.) high, standing on the southern side of a narrow, steep reef which projects 1/3 mile to the northward of the islet. It lies 634 miles 269° true from Siluag Islet.
Alice Channel is the deep channel between Panguan Islet and Bajapa Reef to the northeast and Mataking Islet and Reef to the southwest. It is over 6 miles wide at the narrowest part between the south point of Bajapa Reef and Mataking Islet. The boundary between the Commonwealth of the Philippines and British North Borneo passes through this channel.
Bank.-A bank, composed of coral and sand, on which the least depth obtained was 614 fathoms (11.4 m.), lies near the southern entrance to Alice Channel, in latitude 4°31' N., longitude 119°04'30'' E. It is about 1 mile long in a north and south direction and about 12 mile wide.
Currents.—The tidal streams run strongly, especially in the vicinity of Panguan Islet and Bajapa Reef, flood southward and westward and ebb northward and eastward with a velocity of 2 to 212 knots.
7. NORTH COAST OF BORNEO
(Charts 4707, 4720, and 4722)
This chapter gives a brief description of that portion of the northern coast of Borneo and the off-lying islands and reefs bordering Philippine waters.
The principal harbor and chief place of trade is Sandakan, the seat of government of British North Borneo, within whose territory the greater portion of the area under discussion lies.
Monsoons and winds.-On this coast the northeast monsoon begins about the middle of October and continues till the middle of April. During a greater part of the time the wind blows steadily and with moderate strength from the north and east, gradually dying out. In the course of this monsoon, more particularly in December and January, there are generally one, two, or three steady, moderate gales lasting from 3 to 9 days; at other times the wind is à moderate breeze, which, beginning about 11 a. m., gets rather stronger toward evening, and dies away in the early morning, when it may be overcome by a gentle land breeze. At the beginning and end of the monsoon the wind is not so strong nor so steady and the land breeze continues till late in the afternoon.
The southwest monsoon lasts from the middle of April till the middle of October. The wind as a rule is not so strong in this monsoon; the land breeze in the morning is more marked and the gales are not so heavy nor so long continued as in the northeast monsoon. On the other hand, there are frequently squalls in the afternoon and evening lasting for an hour or two, and sometimes blowing with the force of a fresh gale. Neither in this monsoon nor in the northeast monsoon does the wind rise to the strength of a storm nor even to a whole gale.
The prevailing winds in the afternoon during the southwest monsoon on this part of the coast of Borneo are generally east to south; at night there is usually a land breeze.
Rainfall.—The annual rainfall near the coast ranges from 101 to 157 inches, with an average of 124 inches.
The true wet season occurs in the northeast monsoon, and includes the months of November, December, and January, and generally part of October or February, or both. During this season the greater part of the rain falls from a uniform dull-gray sky and is pretty well equally distributed between day and night, but the rain is not continuous.
The true dry season immediately follows this true wet season, and includes March, April, and May, and generally part of February. During this time any rain that falls generally occurs in showers at
night or early morning, and no month passes without several showers. This true dry season is followed by a period of moderate rainfall
, beginning usually about June, the first month or 6 weeks of which may almost be called a second wet season and the rest of the period up to the beginning of the true wet season a second dry season.
As, however, the limits of these two are ill defined, their characters similar, and the difference in rainfall comparatively small, it is better to consider them together as a sort of intermediate season. During this period the rain falls chiefly in heavy squalls (either with thunder or from thundery clouds), occurring most frequently in the afternoon or evening, but is not confined to that time; it is during these squalls that the heaviest falls of rain occur. On June 15, 1884, 2.05 inches well in 40 minutes.
Climate.-- The climate is noted for nothing more than for its equability and the absence of extremes. The temperature, rainfall
, winds, natural phenomena generally, and the diseases are, for a tropical country, of the most mild and temperate types.
Temperature. The temperature recorded on this coast has ranged between the extremes of 67.5° and 94.5°; but the difference in temperature between the various seasons of the year is very slight. The lowest average temperature (790) for both day and night is during the wet season, in December and January; the highest average during the night occurs during the dry season, in April and May (74°); and the highest average temperature during the day occurs in August and September (89°).
The absence of tornadoes, cyclones, and earthquakes is to be noted. The peculiar phenomena of tropical climates generally are found here; thunderstorms, with much sheet lightning, are frequent during July, August, and September and are sometimes severe. Mirage is generally present in the afternoon to a slight degree; phosphorescence occurs in great perfection in Sandakan Harbor.
On the whole, the country appears to be fairly healthy for the Tropics, less so than Singapore, but much better than the Dutch islands south of the Equator. There is a considerable amount of intermittent fever and visitors are frequently attacked, but the disease is seldom fatal to Europeans.
Tides and currents.—The tidal wave that enters the Sulu Sea from the China Sea by Balabac Strait and Banguey Channel penetrates as far as the northeast point of the island, where it meets the wave from the Celebes Sea, which enters by the Sibutu Channel. Along the east coast the tide is mostly semidiurnal while along the northeast coast it is chiefly diurnal. At Dent Haven the spring range is approximately 312 feet (1.1 m.), at Sandakan the diurnal range is about 5 feet (1.5 m.).
On the coast between Mallawalle and Sandakan no regular tidal stream is perceptible, but when the northeast monsoon is blowing steadily there appears to be a constant set northwestward.