From Keeling I sland our course was slower and more variable,often taking us into great depths.Several times they made use of the inclined planes,which certain internal levers placed obliquely to the waterline.I n that way we went about two miles,but without ever obtaining the greatest depths of the I ndian Sea,which soundings of seven thousand fathoms have never reached.
As to the temperature of the lower strata,the thermometer invariably indicated 4@above zero.I only observed that in the upper regions the water was always colder in the high levels than at the surface of the sea.
On the 25th of January the ocean was entirely deserted;the Nautilus passed the day on the surface,beating the waves with its powerful screw and making them rebound to a great height.Who under such circumstances would not have taken it for a gigantic cetacean?
Three parts of this day I spent on the platform.I watched the sea.
Nothing on the horizon,till about four o'clock a steamer running west on our counter.Her masts were visible for an instant,but she could not see the Nautilus,being too low in the water.
I fancied this steamboat belonged to the P.O.Company,which runs from Ceylon to Sydney,touching at King George's Point and Melbourne.
At five o'clock in the evening,before that fleeting twilight which binds night to day in tropical zones,Conseil and I were astonished by a curious spectacle.
It was a shoal of argonauts travelling along on the surface of the ocean.
We could count several hundreds.They belonged to the tubercle kind which are peculiar to the I ndian seas.
These graceful molluscs moved backwards by means of their locomotive tube,through which they propelled the water already drawn in.Of their eight tentacles,six were elongated,and stretched out floating on the water,whilst the other two,rolled up flat,were spread to the wing like a light sail.
I saw their spiral-shaped and fluted shells,which Cuvier justly compares to an elegant skiff.Aboat indeed!
It bears the creature which secretes it without its adhering to it.
For nearly an hour the Nautilus floated in the midst of this shoal of molluscs.Then I know not what sudden fright they took.
But as if at a signal every sail was furled,the arms folded,the body drawn in,the shells turned over,changing their centre of gravity,and the whole fleet disappeared under the waves.
Never did the ships of a squadron manoeuvre with more unity.
At that moment night fell suddenly,and the reeds,scarcely raised by the breeze,lay peaceably under the sides of the Nautilus.
The next day,26th of January,we cut the equator at the eighty-second meridian and entered the northern hemisphere.
During the day a formidable troop of sharks accompanied us,terrible creatures,which multiply in these seas and make them very dangerous.They were "cestracio philippi"sharks,with brown backs and whitish bellies,armed with eleven rows of teeth--eyed sharks--their throat being marked with a large black spot surrounded with white like an eye.There were also some I sabella sharks,with rounded snouts marked with dark spots.
These powerful creatures often hurled themselves at the windows of the saloon with such violence as to make us feel very insecure.
At such times Ned Land was no longer master of himself.
He wanted to go to the surface and harpoon the monsters,particularly certain smooth-hound sharks,whose mouth is studded with teeth like a mosaic;and large tiger-sharks nearly six yards long,the last named of which seemed to excite him more particularly.
But the Nautilus,accelerating her speed,easily left the most rapid of them behind.
The 27th of January,at the entrance of the vast Bay of Bengal,we met repeatedly a forbidding spectacle,dead bodies floating on the surface of the water.They were the dead of the I ndian villages,carried by the Ganges to the level of the sea,and which the vultures,the only undertakers of the country,had not been able to devour.
But the sharks did not fail to help them at their funeral work.
About seven o'clock in the evening,the Nautilus,half-immersed,was sailing in a sea of milk.At first sight the ocean seemed lactified.
Was it the effect of the lunar rays?No;for the moon,scarcely two days old,was still lying hidden under the horizon in the rays of the sun.
The whole sky,though lit by the sidereal rays,seemed black by contrast with the whiteness of the waters.
Conseil could not believe his eyes,and questioned me as to the cause of this strange phenomenon.Happily I was able to answer him.
"It is called a milk sea,"I explained."Alarge extent of white wavelets often to be seen on the coasts of Amboyna,and in these parts of the sea.""But,sir,"said Conseil,"can you tell me what causes such an effect?
for I suppose the water is not really turned into milk.""No,my boy;and the whiteness which surprises you is caused only by the presence of myriads of infusoria,a sort of luminous little worm,gelatinous and without colour,of the thickness of a hair,and whose length is not more than seven-thousandths of an inch.
These insects adhere to one another sometimes for several leagues.""Several leagues!"exclaimed Conseil.
"Yes,my boy;and you need not try to compute the number of these infusoria.
You will not be able,for,if I am not mistaken,ships have floated on these milk seas for more than forty miles."Towards midnight the sea suddenly resumed its usual colour;but behind us,even to the limits of the horizon,the sky reflected the whitened waves,and for a long time seemed impregnated with the vague glimmerings of an aurora borealis.
