The Home Of The Blizzard Part 17

The observations made in the "Absolute Hut", carried out at frequent intervals and on each occasion occupying two men for several hours together, are necessary to obtain standard values as a check upon the graphic record of the self-recording instruments which run day and night in the "Magnetograph House".

But this is another story. Three hours, sitting writing figures in a temperature of -15 degrees F., is no joke. The magnetician is not so badly off, because he is moving about, though he often has to stop and warm his fingers, handling the cold metal.

The Magnetograph House had by far the most formidable name. The Hut, though it symbolized our all in all, sounded very insignificant unless it were repeated with just the right intonation. The Absolute Hut had a superadded dignity. The Hangar, in pa.s.sing, scarcely seemed to have a right to a capital H. The Transit House, on the and other hand, was the only dangerous rival to the first mentioned. But what's in a name?

If the Magnetograph House had been advertised, it would have been described as "two minutes from the Hut." This can easily be understood, for the magnetician after leaving home is speedily blown over a few hillocks and sastrugi, and, coming to an ice-flat about one hundred and fifty yards wide, swiftly slides over it, alighting at the snow-packed door of his house. The outside porch is just roomy enough for a man to slip off burberrys and crampons. The latter are full of steel spikes, and being capable of upsetting magnetic equilibrium, are left outside.

Walking in soft finnesko, the magnetician opens an inner door, to be at once accosted by darkness, made more intense after the white glare of the snow. His eyes grow accustomed to the blackness, and he gropes his way to a large box almost concealing the feeble glimmer of a lamp. The lamp is the source of the light, projected on to small mirrors attached to the magnetic needles of three variometers. A ray of light is reflected from the mirrors for several feet on to a slit, past which revolves sensitized photographic paper folded on a drum moving by clockwork. The slightest movements of the suspended needles are greatly magnified, and, when the paper is removed and developed in a dark-room, a series of intricate curves denoting declination, horizontal intensity and vertical force, are exquisitely traced. Every day the magnetician attends to the lamp and changes papers; also at prearranged times he tests his "scale values" or takes a "quick run."

To obtain results as free as possible from the local attraction of the rocks in the neighbourhood, Webb resolved to take several sets of observations on the ice-sheet. In order to make the determinations it was necessary to excavate a cave in the glacier. This was done about three-quarters of a mile south of the Hut in working s.h.i.+fts of two men.

A fine cavern was hewn out, and there full sets of magnetic observations were taken under ideal conditions.

On sledging journeys the "dip" and declination were both ascertained at many stations, around and up to within less than half a degree of the South Magnetic Pole.

While the wind rushed by at a maddening pace and stars flashed like jewels in a black sky, a glow of pale yellow light overspread the north-east horizon--the aurora. A rim of dark, stratus cloud was often visible below the light which brightened and diffused till it curved as a low arc across the sky. It was eerie to watch the contour of the arc break, die away into a delicate pallor and reillumine in a travelling riband. Soon a long ray, as from a searchlight, flashed above one end, and then a row of vertical streamers ran out from the arc, probing upwards into the outer darkness. The streamers waxed and waned, died away to be replaced and then faded into the starlight. The arc lost its radiance, divided in patchy fragments, and all was dark once more.

This would be repeated again in a few hours and irregularly throughout the night, but with scenic changes behind the great sombre pall of the sky. North-west, northeast, and south-east it would elusively appear in nebulous blotches, flitting about to end finally in long bright strands in the zenith, crossing the path of the "milky way."

By the observer, who wrote down his exact observations in the meteorological log, this was called a "quiet night."

At times the light was nimble, flinging itself about in rich waves, warming to dazzling yellow-green and rose. These were the nights when "curtains" hung festooned in the heavens, alive, rippling, dancing to the lilt of lightning music. Up from the horizon they would mount, forming a vortex overhead, soundless within the silence of the ether.

A "brilliant display," we would say, and the observer would be kept busy following the track of the evanescent rays.

Powerless, one was in the spell of an all-enfolding wonder. The vast, solitary snow-land, cold-white under the sparkling star-gems; l.u.s.trous in the radiance of the southern lights; furrowed beneath the icy sweep of the wind. We had come to probe its mystery, we had hoped to reduce it to terms of science, but there was always the "indefinable" which held aloof, yet riveted our souls.

The aurora was always with us, and almost without exception could be seen on a dark, driftless night. The nature of the aurora polaris has not yet been finally demonstrated, though it is generally agreed to be a discharge of electricity occurring in the upper, more rarefied atmosphere. The luminous phenomena are very similar to those seen when a current of electricity is pa.s.sed through a vacuum tube.

One receives a distinct impression of nearness, watching the s.h.i.+mmering edges of the "curtains" in the zenith, but all measurements indicate that they never descend nearer than a few miles above the land-surface.

Careful records were taken to establish a relation between magnetic storms and aurorae, and a good deal of evidence was ama.s.sed to support the fact that auroral exhibitions correspond with periods of great magnetic disturbance. The displays in Adelie Land were found to be more active than those which occur in higher lat.i.tudes in the Ross Sea.

An occupation which helped to introduce variety in our life was the digging of ice-shafts. For the purpose of making observations upon its structure and temperature various excavations were made in the sea-ice, in the ice of the glacier, and in that of the freshwater lakes. The work was always popular. Even a whole day's labour with a pick and shovel at the bottom of an ice-hole never seemed laborious. It was all so novel.

A calm morning in June, the sky is clear and the north ablaze with the colours of sunrise--or is it sunset? The air is delicious, and a cool waft comes down the glacier. A deep ultramarine, shading up into a soft purple hue, blends in a colour-scheme with the lilac plateau. Two men crunch along in spiked boots over snow mounds and polished sastrugi to the harbour-ice. The sea to the north is glazed with freezing spicules, and over it sweep the petrels--our only living companions of the winter.

It is all an inspiration; while hewing out chunks of ice and shovelling them away is the acute pleasure of movement, exercise.

The men measure out an area six feet by three feet, and take a preliminary temperature of the surface-ice by inserting a thermometer in a drilled hole. Then the ice begins to fly, and it is not long before they are down one foot. Nevertheless it would surprise those acquainted only with fresh water ice to find how tough, sticky and intractable is sea-ice. It is always well to work on a definite plan, channelling in various directions, and then removing the intervening lumps by a few rough sweeps of the pick. At a depth of one foot, another temperature is taken, and some large samples of the ice laid by for the examination of their crystalline structure. This is repeated at two feet, and so on, until the whole thickness is pierced to the sea-water beneath. At three feet brine may begin to trickle into the hole, and this increases in amount until the worker is in a puddle. The leakage takes place, if not along cracks, through capillary channels, which are everywhere present in sea-ice.

It is interesting to note the temperature gradually rise during the descent. At the surface the ice is chilled to the air-temperature, say -10 degrees F., and it rises in a steep gradient to approximately 28 degrees F.; close to the freezing-point of sea water. The sea-ice in the boat-harbour varied in thickness during the winter between five and seven feet.

In contrast with sea-ice, the ice of a glacier is a marvel of prismatic colour and gla.s.sy brilliance. This is more noticeable near the surface when the sun is s.h.i.+ning. Deep down in a shaft, or in an ice-cavern, the sapphire reflection gives to the human face quite a ghastly pallor.

During the high winds it was always easy to dispose of the fragments of ice in the earlier stages of sinking a shaft. To be rid of them, all that was necessary was to throw a shovelful vertically upwards towards the lee-side of the hole, the wind then did the rest. Away the chips would scatter, tinkling over the surface of the glacier. Of course, when two men were at work, each took it in turns to go below, and the one above, to keep warm, would impatiently pace up and down. Nevertheless, so cold would he become at times that a heated colloquy would arise between them on the subject of working overtime. When the shaft had attained depth, both were kept busy. The man at the pit's mouth lowered a bucket on a rope to receive the ice and, in hauling it up, handicapped with clumsy mitts, he had to be careful not to drop it on his companion's head.

The structural composition of ice is a study in itself. To the cursory glance a piece of glacier-ice appears h.o.m.ogeneous, but when dissected in detail it is found to be formed of many crystalline, interlocking grains, ranging in size from a fraction of an inch to several inches in diameter. A grain-size of a half to one inch is perhaps commonest in Antarctic glacier-ice.

The history of Antarctic glacier-ice commences with the showers of snow that fall upon the plateau. The snow particles may be blown for hundreds of miles before they finally come to rest and consolidate.

The consolidated snow is called neve, the grains of which are one-twenty-fifth to one hundredth of an inch in diameter, and, en ma.s.se, present a dazzling white appearance on account of the air s.p.a.ces which occupy one-third to one-half of the whole. In time, under the influence of a heavy load of acc.u.mulated layers of neve, the grains run together and the air s.p.a.ces are eliminated. The final result is clear, transparent ice, of a more or less sapphire-blue colour when seen in large blocks. It contains only occasional air-bubbles, and the size of the grains is much increased.

Lake-ice, freezing from the surface downwards, is built up of long parallel prisms, like the cells of a honey-comb on a large scale. In a lakelet near the Hut this was beautifully demonstrated. In some places cracks and fissures filled with snow-dust traversed the body of the ice, and in other places long strings of beaded air-bubbles had become entangled in the process of freezing. To lie down on the clear surface and gaze "through the looking-gla.s.s" to the rocky bottom, twenty feet below, was a glimpse into "Wonderland."

In the case of sea-ice, the simple prismatic structure is complicated owing to the presence of saline matter dissolved in the sea water.

The saline tracts between the prisms produce a milky or opalescent appearance. The prisms are of fresh water ice, for in freezing the brine is rejected and forced to occupy the interstices of the prisms. Water of good drinking quality can be obtained by allowing sea water ice to thaw partially. The brine, of lower freezing-point, flows away, leaving only fresh water ice behind. In this way blocks of sea-ice exposed to the sun's rays are relieved of their salty const.i.tuents, and crumble into pellucid gravel when disturbed.

A popular subject commanding general interest, apart from the devoted attention of specialists, was zoological collecting. Seals and birds were made the prey of every one, and dredging through the sea-ice in winter and spring was always a possible diversion.

It was a splendid sight to watch the birds sailing in the high winds of Adelie Land. In winds of fifty to seventy miles per hour, when with good crampons one had to stagger warily along the ice-foot, the snow petrels and Antarctic petrels were in their element. Wheeling, swinging, sinking, planing and soaring, they were radiant with life--the wild spirits of the tempest. Even in moderate drift, when through swirling snow the vistas of sea whitened under the flail of the wind, one suddenly caught the silver flash of wings and a snow petrel glided past.

But most memorable of all were certain winter mornings of unexpected calm, when ruddy clouds tessellated the northern sky and were mirrored in the freezing sea. Then the petrels would be en fete, flying over from the east following the line of the Barrier, winding round the icy coves, darting across the jutting points and ever onward in their long migration. In the summer they flew for weeks from the west--a never-ending string of snow, silver-grey and Antarctic petrels, and Cape pigeons. The silver-grey petrels and Cape pigeons were only abroad during that season and were accompanied by skua gulls, giant petrels, Wilson petrels, and penguins. The penguins remained in Adelie Land for the longest period--almost six months, the skua gulls and giant petrels for five months, and the rest for a shorter period--the tolerable season of midsummer.

Birds that haunt the wide oceans all make use of the soaring principle in flight, some much more than others. The beautiful sliding sweep of the albatross is the most familiar example. With wings outspread, it is a miniature aeroplane requiring no engines, for the wind itself supplies the power. A slight movement of the tail-feathers and wing-tips controls its balance with nice precision. Birds employing this method of flight find their home in the zone of continuous steady winds which blow across the broad wastes of the southern seas.

Many petrels on the wing were shot during the winter. Laseron, who prepared the skins of our Adelie Land collection, determined, in the case of a number of specimens, the ratio of weight to horizontal area exposed to the wind. This subject is one which has lately exercised the curiosity of aviators. The ratios are those evolved by nature, and, as such, should be wellnigh perfect. Below is appended a table of the results obtained.

WEIGHT OF CERTAIN ANTARCTIC BIRDS IN RELATION TO WING AREAS

(Stated in pounds per square foot of wing surface)

Each is the mean of several determinations by Laseron

Giant petrel........... 3.5 Albatross ........... 2.4 Antarctic petrel......... 2.1 Skua gull ........... 1.6 Snow petrel ........... 1.1 Wilson petrel........... 0.6

Values from a book of reference quoted for comparison

Bat ........... 0.1 Sparrow ........... 0.4 Wild goose ........... 1.7

During the winter, for a long period, no seals ventured ash.o.r.e, though a few were seen swimming in the bay. The force of the wind was so formidable that even a heavy seal, exposed in the open, broadside-on, would be literally blown into the water. This fact was actually observed out on the harbour-ice. A Weddell seal made twelve attempts to land on a low projecting shelf--an easy feat under ordinary circ.u.mstances. The wind was in the region of eighty-five miles per hour, and every time the clumsy, ponderous creature secured its first hold, back it would be tumbled. Once it managed to raise itself on to the flat surface, and, after a breathing spell, commenced to shuffle towards the shelter of some pinnacles on one side of the harbour. Immediately its broad flank was turned to the wind it was rolled over, hung for a few seconds on the brink, and then splashed into the sea. On the other hand, during the spring, a few more ambitious seals won their way ash.o.r.e in high winds; but they did not remain long in the piercing cold, moving uneasily from place to place in search of protecting hummocks and finally taking to the water in despair. Often a few hours of calm weather was the signal for half a dozen animals to land. The wind sooner or later sprang up and drove them back to their warmer element.

Under the generic name, seal, are included the true or hair seals and the sea-bears or fur seals. Of these the fur seals are sub-polar in distribution, inhabiting the cold temperate waters of both hemispheres, but never living amongst the polar ice. The southern coast of Australia and the sub-antarctic islands were their favourite haunts, but the ruthless slaughter of the early days practically exterminated them. From Macquarie Island, for example, several hundred thousand skins were taken in a few years, and of late not a single specimen has been seen.

Closely related to the fur seals are the much larger animals popularly known as sea-lions. These still exist in great numbers in south temperate waters. Both are distinguished from the hair seals by one obvious characteristic: their method of propulsion on land is by a "lolloping" motion, in which the front and hind flippers are used alternately. The hair seals move by a caterpillar-like shuffle, making little or no use of their flippers; and so, the terminal parts of their flippers are not bent outwards as they are in the fur seals and sea-lions.

Of the hair seals there are five varieties to be recognized in the far South. The Weddell seals, with their mottled-grey coats, are the commonest. They haunt the coasts of Antarctica and are seldom found at any distance from them. Large specimens of this species reach nine and a half feet in length.

The crab-eater seal, a smaller animal, lives mostly on the pack-ice.

Lying on a piece of floe in the suns.h.i.+ne it has a glistening, silver-grey skin--another distinguis.h.i.+ng mark being its small, handsome head and short, thin neck. Small crustaceans form its princ.i.p.al food.

The Ross seal, another inhabitant of the pack-ice, is short and bulky, varying from a pale yellowish-green on the under side to a dark greenish-brown on the back. Its neck is ample and bloated, and when distended in excitement reminds one of a pouter-pigeon. This rare seal appears to subsist mainly on squid and jelly-fish.

The sea-leopard, the only predacious member of the seal family, has an elongated agile body and a large head with ma.s.sive jaws. In general it has a mottled skin, darker towards the back. It lives on fish, penguins and seals. Early in April, Hurley and McLean were the first to obtain proof that the sea-leopard preyed on other seals. Among the broken floe-ice close beneath the ice-cliffs to the west of Winter Quarters, the wind was driving the dead body of a Weddell seal which swept past them, a few yards distant, to the open water. Then it was that a sea-leopard was observed tearing off and swallowing great pieces of flesh and blubber from the carcase.

The last variety of hair seal, the sea elephant, varies considerably from the preceding. Reference has already been made to the species earlier in the narrative. The habitat of these monstrous animals ranges over the cold, south-temperate seas; sea elephants are but occasional visitors to the ice-bound regions. Although they have been exterminated in many other places, one of their most populous resorts at the present day is Macquarie Island.

In the case of all the hair seals a layer of blubber several inches in thickness invests the body beneath the skin and acts as a conserver of warmth. They are largely of value for the oil produced by rendering down the blubber. The pelts are used for leather.

The operation of skinning seals for specimens, in low temperatures and in the inevitable wind, was never unduly protracted. We were satisfied merely to strip off the skin, leaving much blubber still adhering to it.

In this rough condition it was taken into the work-room of the Hut to be cleaned. The blubber froze, and then had the consistency of hard soap and was readily severed from the pelt. It was found that there exuded amongst the frozen blubber a thin oil which remained liquid when collected and exposed to low temperatures. This oil was used to lubricate the anemometer and other instruments exposed outside.