258 
VOYAGB OF THE POTOMAC. 
[March, 
addition to this, it was requisite to lie in a situation where were 
greater faciUties for taking in wood and water than the town could 
afford, and a more favourable spot for that purpose than the one 
selected could hardly be desired. At any rate, it was decidedly 
preferable to Batavia, where such duty must have greatly exposed 
both officers and men to the baleful efFects of insalubrious exha- 
lations which surround the Dutch capital ; besides the gratification 
derived from an opportunity of seeing so much of this out-of-the- 
way portion of the island. It is even doubtful whether the water 
in the vicinity of Batavia be wholesome for a ship's use. Mr. 
Barrow, before quoted, says, that "a glass of water taken out of 
the canal of Batavia, becomes, in the course of a few hours, a 
mass of animated matter, the minute portions of which, multiply- 
ing by division and subdivision, move about with astonishing 
rapidity. The bay (of Batavia), swarming with myriads of 
living creatures, exhibits, in the night-time, a phosphorescent light 
like a sheet of fire. The stream of fresh water which falls into 
it, being more highly charged with animal life, is distinctly traced 
in the bay, by a train more luminous and brilliant than the rest of 
the surface, appearing like another milky-way in the midst of a 
firmament of stars." 
Having now completed her supply of wood and water, the Po- 
tomac got under way on the morning of Monday, the nineteenth, 
and shaped her course for Batavia Roads, a distance of more than 
twenty leagues east from her recent anchorage. This was a pas- 
sage of unusual beauty and interest, the surface of the sea being 
thickly studded with little evergreen islands, of almost every 
shape and variety. The indolent Dutch colonists, despairing of 
ever furnishing a name for each, have lumped the whole group, 
and given it the name of the Thousand Islands. The French 
did the same at the head of the St. Lawrence. The sea here, 
fine weather and calms, favouring an increase of heat above the mean temperature, 
is liable to be succeeded by a typhoon. 
When the horizon is very clear in some parts, and the summits of the hills or 
islands obscured by dense black clouds, there is some irregularity in the atmosphere, 
and stormy weather may be apprehended ; but in reality typhoons are seldom pre- 
ceded by any certain sign or indication. Marine barometers, if well constructed, 
seem to afford the best means to anticipate these tempests ; for the mercury is 
sometimes liable to a greater fall on the south coast of China, than might be expected 
within the tropics. 
