Extraordinary precautions were taken for_The South Pole; an account of the Norwegian Antarctic expedition in the "Fram," 1910-12

sides, which were particularly exposed to destruction by ice-pressure,

and which, on account of their form, compose the weakest part of the

hull. These precautions will best be seen in the sections (Figs. 3

and 4). Under each beam in both decks were placed diagonal stays of

fir (6 x 10 inches), almost at right angles to the ship's sides, and

securely fastened to the sides and to the beams by wooden knees. There

are 68 of these stays distributed over the ship. In addition, there

are under the beams three rows of vertical stanchions between decks,

and one row in the lower hold from the keelson. These are connected

to the keelson, to the beams, and to each other by iron bands. The

whole of the ship's interior is thus filled with a network of braces

and stays, arranged in such a way as to transfer and distribute the

pressure from without, and give rigidity to the whole construction. In

the engine and boiler room it was necessary to modify the arrangement

of stays, so as to give room for the engines and boiler. All the iron,

with the exception of the heaviest forgings, is galvanized.

When Otto Sverdrup was to use the Fram for his Polar expedition,

he had a number of alterations carried out. The most important of

these consisted in laying a new deck in the fore part of the ship,

from the bulkhead forward of the engine-room to the stem, at a height

of 7 feet 4 inches (to the upper side of the planks) above the old

fore-deck. The space below the new deck was fitted as a fore-cabin,

with a number of state-rooms leading out of it, a large workroom,

etc. The old chart-house immediately forward of the funnel was removed,

and in its place a large water-tank was fitted. The foremast was

raised and stepped in the lower deck. A false keel, 10 inches deep

and 12 inches broad, was placed below the keel. A number of minor

alterations were also carried out.

After the Fram returned in 1902 from her second expedition under

Captain Sverdrup, she was sent down to Horten to be laid up in the

Naval Dockyard.

Not long after the vessel had arrived at the dockyard, Captain Sverdrup

proposed various repairs and alterations. The repairs were carried

out in part, but the alterations were postponed pending a decision

as to the future employment of the vessel.

The Fram then lay idle in the naval harbour until 1905, when she was

used by the marine artillery as a floating magazine. In the same

year a good deal of the vessel's outfit (amongst other things all

her sails and most of her rigging) was lost in a fire in one of the

naval storehouses, where these things were stored.

In 1903 the ship's keel and stem (which are of elm and oak) were

sheathed with zinc, while the outer sheathing (ice-skin), which is of

greenheart, was kept coated with coal-tar and copper composition. In

1907 the whole outer sheathing below the water-line was covered with

zinc; this was removed in 1910 when the ship was prepared for her

third commission under Roald Amundsen.

In 1907 a thorough examination of the vessel was made, as it was

suspected that the timber inside the thick cork insulation that

surrounded the cabins had begun to decay.

On previous expeditions the cabins, provision hold aft, and workrooms

forward of the fore-cabin, had been insulated with several thicknesses

of wooden panelling. The interstices were filled with finely-divided

cork, alternately with reindeer hair and thick felt and linoleum. In

the course of years damp had penetrated into the non-conducting

material, with the result that fungus and decay had spread in the

surrounding woodwork. Thus it was seen during the examination in 1907

that the panelling and ceiling of the cabins in question were to a

great extent rotten or attacked by fungus. In the same way the under

side of the upper deck over these cabins was partly attacked by fungus,

as were its beams, knees, and carlings. The lower deck, on the other

hand, was better preserved. The filling-in timbers of spruce or fir

between the frame-timbers in the cabins were damaged by fungus, while

the frame-timbers themselves, which were of oak, were good. The outer

lining outside the insulated parts was also somewhat damaged by fungus.

In the coal-bunkers over the main-deck the spruce knees were partly

rotten, as were some of the beams, while the lining was here fairly

good.

The masts and main-topmast were somewhat attacked by decay, while

the rest of the spars were good.

During and after the examination all the panelling and insulation

was removed, the parts attacked by fungus or decay were also removed,

and the woodwork coated with carbolineum or tar. The masts and various

stores and fittings were taken ashore at the same time.

It was found that the rest of the vessel-that is, the whole of the

lower part of the hull right up to the cabin deck-was perfectly sound,

and as good as new. Nor was there any sign of strain anywhere. It is

difficult to imagine any better proof of the excellence of the vessel's

construction; after two protracted expeditions to the most northern

regions to which any ship has ever penetrated, where the vessel was

often exposed to the severest ice-pressure, and in spite of her being

(in 1907) fifteen years old, the examination showed that her actual

hull, the part of the ship that has to resist the heavy strain of

water and ice, was in just as good condition as when she was new.

The vessel was then left in this state until, as already mentioned,

Roald Amundsen and her builder, Colin Archer, came down to the dockyard

on June 1, 1908, and with the necessary assistance made an examination

of her.

After some correspondence and verbal conferences between Roald Amundsen

and the dockyard, the latter, on March 9, 1909, made a tender for the

repairs and alterations to the Fram. The repairs consisted of making

good the damage to the topsides referred to above.

The alterations were due in the first instance to the circumstance

that the steam-engine and boiler (the latter had had its flues burnt

out on Sverdrup's expedition) were to be replaced by an oil-motor; as

a consequence of this the coal-bunkers would disappear, while, on the

other hand, a large number of oil-tanks, capable of containing about

90 tons of oil, were to be put in. It was also considered desirable

to rig square-sails on the foremast in view of the great distances

that were to be sailed on the proposed expedition.

The present arrangement of the vessel will best be followed by

referring to the elevation and plan (Figs. 1 and 2).

In the extreme after-part of the lower hold is placed the 180

horse-power Diesel engine, surrounded by its auxiliary machinery

and air-reservoirs.

In addition, some of the tanks containing the fuel itself are placed

in the engine-room (marked O); the other tanks shown in the engine-room

(marked 9) serve for storing lubricating oil. The existing engine-room

was formerly the engine and boiler room, with coal-bunkers on both

sides in the forward part. Forward of the watertight bulkhead of the

engine-room we have, in the lower hold, the main store of oil-fuel,

contained in tanks (marked O) of various sizes, on account of their

having to be placed among the numerous diagonal stays. The tanks are

filled and emptied by means of a pump and a petroleum hose through a

manhole in the top, over which, again, are hatches in the deck above;

no connecting pipes are fitted between the different tanks, for fear

they might be damaged by frost or shock, thus involving a risk of

losing oil. The main supply tank for fuel is placed over the forward

side of the engine-room, where it is supported on strong steel girders;

inside this tank, again, there are two smaller ones -- settling tanks

-- from which the oil is conveyed in pipes to the engine-pumps. The

main tank is of irregular shape -- as will be seen from the drawing

-- since a square piece is taken out of its starboard after-corner

for a way down into the engine-room. Besides this way down, an

emergency way leads up from the engine-room, right aft, to one of the

after-cabins. The oil hold is closed forward by a watertight bulkhead,

which goes up to the main-deck. The hold forward of the oil-supply

is unaltered, and serves for stowing cargo (mainly provisions),

as does the hold above the oil-supply and below the main-deck.

On the main-deck right aft we now find a space arranged on each side

of the well for the propeller and rudder; the lower part of this

space is occupied by two tanks for lamp-oil, and above the tanks is

a thin partition, which forms the floor of two small sail-rooms, with

hatches to the deck above. Around the mizzenmast is the after-saloon,

with eight cabins leading out of it. From the forward end of the

after-saloon two passages lead to the large workroom amidships. These

passages run past what were formerly coal-bunkers, but are now arranged

as cabins, intended only to be used in milder climates, as they are

not provided with any special insulation. From the port passage a

door leads to the engine-room companion. In the after-part of the

large workroom is the galley. This room is entirely lined with zinc,

both on walls and ceiling (on account of the danger of fire), while the

deck is covered with lead, on which tiles are laid in cement. Forward

of the galley is the main hatch, and two large water-tanks are fitted

here, one on each side. The remainder of the workroom affords space

for carpenter's benches, turning-lathes, a forge, vices, etc. From

the workroom two doors lead into the fore-saloon with its adjoining

cabins. Amundsen's cabin is the farthest forward on the starboard side,

and communicates with an instrument-room. From the fore-saloon a door

leads out forward, past a sixth cabin.

In the space forward on the main-deck we have the fore-hatch, and

by the side of this a room entirely lined with zinc plates, which

serves for storing furs. Forward of the fur store is fitted a 15

horse-power one-cylinder Bolinder motor for working the capstan; the

main features of its working will be seen in the drawing. There are

two independent transmissions: by belt and by chain. The former is

usually employed. The chain transmission was provided as a reserve,

since it was feared that belt-driving might prove unserviceable in

a cold climate. This fear, however, has hitherto been ungrounded.

Forward of the motor there is a large iron tank to supply water for

cooling it. In the same space are chain-pipes to the locker below

and the heel of the bowsprit. This space also serves as cable-tier.

On the upper deck we find aft, the opening of the rudder-well and

that of the propeller-well, covered with gratings. A piece was added

to the lower part of the rudder to give more rudder area.

Forward of the propeller-well comes the reserve steering-gear, almost

in the same position formerly occupied by the only steering-gear; the

ordinary steering-gear is now moved to the bridge. The old engine-room

companion aft is now removed, and forward of the after-wheel is only

the skylight of the after-saloon. Up through the latter comes the

exhaust-pipe of the main engine. Forward of and round the mizzenmast

is the bridge, which is partly formed by the roofs of the large

chart-house and laboratory amidships and the two houses on each

side. The chart-house occupies the place of the old boiler-room

ventilator, and abuts on the fore-deck. (It is thus a little aft of

the place occupied by the chart-house on Nansen's expedition.) It is

strongly built of timbers standing upright, securely bolted to the

deck. On both sides of this timber work there are panels, 2 inches

thick on the outside and 1 inch on the inside, and the space between

is filled with finely-divided cork. Floor and roof are insulated in

a similar way, as is also the door; the windows are double, of thick

plate-glass. Inside the chart-house, besides the usual fittings for

its use as such, there is a companion-way to the engine-room, and

a hatch over the manhole to the main supply tank for oil-fuel. The

opening in the deck has a hatch, made like the rest of the deck (in

two thicknesses, with cork insulation between); the intention is to

cut off the engine-room altogether, and remove the entrance of this

companion during the drift in the ice through the Polar sea. The side

houses are constructed of iron, and are not panelled; they are intended

for w.c. and lamp-room. On the roof of the chart-house are the main

steering-gear and the engine-room telegraph. On the port side, on the

forward part of the after-deck, a Downton pump is fitted, which can

either be worked by hand or by a small motor, which also serves to

drive the sounding-machine, and is set up on the after-deck. Forward

of the starboard side house is the spare rudder, securely lashed to

deck and bulwarks. On each side of the chart-house a bridge leads to

the fore-deck, with ways down to the workroom and fore-saloon. On

the fore-deck, a little forward of the mainmast, we find the two

ship's pumps proper, constructed of wood. The suction-pipe is of

wood, covered on the outside with lead, so as to ]prevent leakage

through possible cracks in the wood; the valves are of leather,

and the piston of wood, with a leather covering. The pump-action is

the usual nickel action, that was formerly general on our ships, and

is still widely used on smacks. These simple pumps have been shown by

experience to work better than any others in severe cold. The fore-deck

also has skylights over the fore-saloon, the main and fore hatches,

and finally the capstan. This is of the ordinary horizontal type,

from Pusnes Engineering Works; it is driven by the motor below, as

already mentioned. The capstan can also be used as a winch, and it

can be worked by hand-power.

The Fram carries six boats: one large decked boat (29 x 9 x 4 feet)

-- one of the two large boats carried on Nansen's expedition --

placed between the mainmast and the foremast, over the skylight;

three whale-boats (20 x 6 feet), and one large and one small pram; the

two last are carried on davits as shown in the drawing. One of these

whale-boats was left behind on the Ice Barrier, where it was buried

in snow when the ship left. It was brought ashore that the wintering

party might have a boat at their disposal after the Fram had sailed.

For warming the vessel it is intended to use only petroleum. For

warming the laboratory (chart-house) there is an arrangement by which

hot air from the galley is brought up through its forward wall.

The vessel was provided with iron chain plates bolted to the timbers

above the ice-skin. The mizzenmast is new. There was a crack in

the beam that forms the support for the mizzenmast; it was therefore

strengthened with two heavy iron plates, secured by through-bolts. Two

strong steel stanchions were also placed on each side of the engine,

carried down to the frame-timbers. The old mizzenmast has been

converted into a bowsprit and jib-boom in one piece. There are now

standing gaffs on all three masts. The sail area is about 6,640

square feet.

All the cabins are insulated in the same way as before, though it

has been found possible to simplify this somewhat. In general the

insulation consists of:

1. In the cabins, against the ship's side and under the upper deck,

there is first a layer of cork, and over that a double panelling of

wood with tarred felt between.

2. Above the orlop deck aft there is a layer of cork, and above this

a floor of boards covered with linoleum.

3. Under the orlop deck forward there is wooden panelling, with

linoleum over the deck.

Bulkheads abutting on parts of the ship that are not warmed consist

of three thicknesses of boards or planks with various non-conducting

materials, such as cork or felt, between them.

When the vessel was docked before leaving Horten, the zinc sheathing

was removed, as already stated, since fears were entertained that it

would be torn by the ice, and would then prevent the ice from slipping

readily under the bottom during pressure. The vessel has two anchors,

but the former port anchor has been replaced by a considerably

heavier one (1 ton 1 1/2 hundredweight), with a correspondingly

heavier chain-cable. This was done with a special view to the voyage

round Cape Horn.

In order to trim the ship as much as possible by the stern, which

was desirable on account of her carrying a weather helm, a number

of heavy spare stores, such as the old port anchor and its cable,

were stowed aft, and the extreme after-peak was filled with cement

containing round pieces of iron punched out of plates.

Along the railing round the fore-deck strong netting has been placed

to prevent the dogs falling overboard. For the upper deck a loose

wooden grating has been made, so that the dogs shall not lie on

the wet deck. Awnings are provided over the whole deck, with only

the necessary openings for working the ship. In this way the dogs

have been given dry and, as far as possible, cool quarters for the

voyage through the tropics. It is proposed to use the ship's spars as

supports for a roof of boards, to be put up during the drift through

the ice as a protection against falling masses of ice.

The Fram's new engine is a direct reversible Marine-Polar-Motor,

built by the Diesel Motor Co., of Stockholm. It is a Diesel engine,

with four working and two air-pump cylinders, and develops normally

at 280 revolutions per minute 180 effective horse-power, with a

consumption of oil of about 7 3/4 ounces per effective horse-power

per hour. With this comparatively small consumption, the Fram's fuel

capacity will carry her much farther than if she had a steam-engine,

a consideration of great importance in her forthcoming long voyage

in the Arctic Sea. With her oil capacity of about 90 tons, she will

thus be able to go uninterruptedly for about 2,273 hours, or about

95 days. If we reckon her speed under engine power alone at 4 1/2

knots, she will be able to go about 10,000 nautical miles without

replenishing her oil-supply. It is a fault in the new engine that

its number of revolutions is very high, which necessitates the use

of a propeller of small diameter (5 feet 9 inches), and thus of low

efficiency in the existing conditions. This is the more marked on

account of the unusual thickness of the Fram's propeller-post, which

masks the propeller to a great extent. The position of the engine will

be seen in Fig. 1. The exhaust gases from the engine are sent up by

a pipe through the after-saloon, through its skylight, and up to a

large valve on the bridge; from this valve two horizontal pipes run

along the after side of the bridge, one to each side: By means of the

valve the gases can be diverted to one side or the other, according

to the direction of the wind, Besides the usual auxiliary engines,

the main engine drives a large centrifugal bilge-pump, an ordinary

machine bilge-pump, and a fan for use in the tropics.

When the Fram left Christiania in the spring of 1910, after taking

her cargo on board, she drew 17 feet forward and 19 feet 5 inches

aft. This corresponds to a displacement (measured outside the ice-skin)

of about 1,100 tons. The ice-skin was then 12 1/2 inches above the

waterline amidships.

CHAPTER II

Remarks on the Meteorological Observations at Framheim

By B. J. Birkeland

On account of the improvised character of the South Polar Expedition,

the meteorological department on the Fram was not so complete as it

ought to have been. It had not been possible to provide the aerological

outfit at the time of sailing, and the meteorologist of the expedition

was therefore left behind in Norway. But certain things were wanting

even to complete the equipment of an ordinary meteorological station,

such as minimum thermometers and the necessary instructions that should

have accompanied one or two of the instruments. Fortunately, among

the veterans of the expedition there were several practised observers,

and, notwithstanding all drawbacks, a fine series of observations was

obtained during ten months' stay in winter-quarters on the Antarctic

continent. These observations will provide a valuable supplement to

the simultaneous records of other expeditions, especially the British

in McMurdo Sound and the German in Weddell Sea, above all as regards

the hypsometer observations (for the determination of altitude)

on sledge journeys. It may be hoped, in any case, that it will be

possible to interpolate the atmospheric pressure at sea-level in all

parts of the Antarctic continent that were traversed by the sledging

expeditions. For this reason the publication of a provisional working

out of the observations is of great importance at the present moment,

although the general public will, perhaps, look upon the long rows

of figures as tedious and superfluous. The complete working out of

these observations can only be published after a lapse of some years.

As regards the accuracy of the figures here given, it must be noted

that at present we know nothing about possible alterations in the

errors of the different instruments, as it will not be possible to

have the instruments examined and compared until we arrive at San

Francisco next year. We have provisionally used the errors that

were determined at the Norwegian Meteorological Institute before

the expedition sailed; it does not appear, however, that they have

altered to any great extent.

The meteorological outfit on the Fram consisted of the following

instruments and apparatus:

Three mercury barometers, namely:

One normal barometer by Fuess, No. 361 .

One Kew standard barometer by Adie, No. 889.

One Kew marine barometer by Adie, No. 764.

Five aneroid barometers:

One large instrument with thermometer attached, without name

or number.

Two pocket aneroids by Knudsen, Copenhagen, one numbered 1,503.

Two pocket aneroids by Cary, London, Nos. 1,367 and 1,368,

for altitudes up to 5,000 metres (16,350 feet).

Two hypsometers by Casella, with several thermometers.

Mercury thermometers:

Twelve ordinary standard (psychrometer-) thermometers,

divided to fifths of a degree (Centigrade).

Ten ordinary standard thermometers, divided to degrees.

Four sling thermometers, divided to half degrees.

Three maximum thermometers, divided to degrees.

One normal thermometer by Mollenkopf, No. 25.

Toluene thermometers:

Eighteen sling thermometers, divided to degrees.

Three normal thermometers-by Tounelot, No. 4,993, and Baudin,

Nos. 14,803 and 14,804.

Two torsion hair hygrometers of Russeltvedt's construction,

Nos. 12 and 14.

One cup and cross anemometer of Professor Mohn's construction,

with spare cross.

One complete set of precipitation gauges, with Nipher's shield,

gauges for snow density, etc.

Registering instruments:

Two barographs.

Two thermographs.

One hair hygrograph.

A number of spare parts, and a supply of paper and ink for

seven years.

In addition, various books were taken, such as Mohn's "Meteorology,"

the Meteorological Institute's "Guide," psychrometric tables, Wiebe's

steam-pressure tables for hypsometer observations, etc.

The marine barometer, the large aneroid, and one of the barographs,

the four mercury sling thermometers, and two whole-degree standard

thermometers, were kept on board the Fram, where they were used for

the regular observations every four hours on the vessel's long voyages

backwards and forwards.

As will be seen, the shore party was thus left without mercury sling

thermometers, besides having no minimum thermometers; the three maximum

thermometers proved to be of little use. There were also various

defects in the clockwork of the registering instruments. The barographs

and thermographs have been used on all the Norwegian Polar expeditions;

the hygrograph is also an old instrument, which, in the course of

its career, has worked for over ten years in Christiania, where

the atmosphere is by no means merciful to delicate instruments. Its

clockwork had not been cleaned before it was sent to the Fram, as was

done in the case of the other four instruments. The barographs worked

irreproachably the whole time, but one of the thermographs refused

absolutely to work in the open air, and unfortunately the spindle pivot

of the other broke as early as April 17. At first the clockwork of the

hygrograph would not go at all, as the oil had become thick, and it

was not until this had been removed by prolonged severe heating (baking

in the oven for several days) that it could be set going; but then it

had to be used for the thermograph, the mechanism of which was broken,

so that no registration was obtained of the humidity of the air.

The resulting registrations are then as follows: from Framheim, one

set of barograms and two sets of thermograms, of which one gives the

temperature of the air and the other the temperature inside the house,

where the barometers and barograph were placed; from the Fram we have

barograms for the whole period from her leaving Christiania, in 1910,

to her arrival at Buenos Aires for the third time, in 1912.

Of course, none of these registrations can be taken into account in

the provisional working out, as they will require many months' work,

which, moreover, cannot be carried out with advantage until we have

ascertained about possible changes of error in the instruments. But

occasional use has been made of them for purposes of checking, and

for supplying the only observation missing in the ten months.

The meteorological station at Framheim was arranged in this way:

the barometers, barograph, and one thermograph hung inside the house;

they were placed in the kitchen, behind the door of the living-room,

which usually stood open, and thus protected them from the radiant heat

of the range. A thermometer, a hygrometer, and the other thermograph

were placed in a screen on high posts, and with louvred sides,

which stood at a distance of fifteen yards to the south-west of the

house. A little way beyond the screen, again, stood the wind-vane and

anemometer. At the end of September the screen had to be moved a few

yards to the east; the snow had drifted about it until it was only 2

1/2 feet above the surface, whereas it ought to stand at the height

of a man. At the same time the wind-vane was moved. The screen was

constructed by Lindström from his recollection of the old Fram screen.

The two mercury barometers, the Fuess normal, and the Adie standard

barometer, reached Framheim in good condition; as has been said, they

were hung in the kitchen, and the four pocket aneroids were hung by

the side of them. All six were read at the daily observations at 8

a.m., 2 p.m., and 8 p.m. The normal barometer, the instructions for

which were missing, was used as a siphon barometer, both the mercury

levels being read, and the bottom screw being locked fast; the usual

mode of reading it, on the other hand, is to set the lower level at

zero on the scale by turning the bottom screw at every observation,

whereupon the upper level only is set and read. The Adie standard

barometer is so arranged that it is only necessary to read the summit

of the mercury. It appears that there is some difference between

the atmospheric pressure values of the two instruments, but this is

chiefly due to the difficult and extremely variable conditions of

temperature. There may be a difference of as much as five degrees

(Centigrade) between the thermometers of the two barometers, in

spite of their hanging side by side at about the same height from

the floor. On the other hand, the normal barometer is not suited to

daily observations, especially in the Polar regions, and the double

reading entails greater liability of error. That the Adie barometer

is rather less sensitive than the other is of small importance, as

the variations of atmospheric pressure at Framheim were not very great.

In the provisional working out, therefore, the readings of the Adie

barometer alone have been used; those of the normal barometer,

however, have been experimentally reduced for the first and last

months, April and January. The readings have been corrected for the

temperature of the mercury, the constant error of the instrument,

and the variation of the force of gravity from the normal in latitude

45°. The reduction to sea-level, on the other hand, has not been made;

it amounts to 1.1 millimetre at an air temperature of -10° Centigrade.

The observations show that the pressure of the atmosphere is

throughout low, the mean for the ten months being 29.07 inches

(738.6 millimetres). It is lower in winter than in summer, July

having 28.86 inches (733.1 millimetres), and December 29.65 inches

(753.3 millimetres), as the mean for the month, a difference of

20.2 millimetres. The highest observation was 30.14 inches (765.7

millimetres) on December 9, and the lowest 28.02 inches (711.7

millimetres) on May 24, 1911; difference, 54 millimetres.

Air Temperature and Thermometers.

As has already been stated, minimum thermometers and mercury sling

thermometers were wanting. For the first six months only toluene sling

thermometers were used. Sling thermometers are short, narrow glass

thermometers, with a strong loop at the top; before being read they

are briskly swung round at the end of a string about half a yard long,

or in a special apparatus for the purpose. The swinging brings the

thermometer in contact with a great volume of air, and it therefore

gives the real temperature of the air more readily than if it were

hanging quietly in the screen.

From October 1 a mercury thermometer was also placed in the screen,

though only one divided to whole degrees; those divided to fifths

of a degree would, of course, have given a surer reading. But it is

evident, nevertheless, that the toluene thermometers used are correct

to less than half a degree (Centigrade), and even this difference

may no doubt be explained by one thermometer being slung while the

other was fixed. The observations are, therefore, given without any

corrections. Only at the end of December was exclusive use made of

mercury thermometers. The maximum thermometers taken proved of so

little use that they were soon discarded; the observations have not

been included here.

It was due to a misunderstanding that mercury thermometers were

not also used in the first half-year, during those periods when

the temperature did not go below the freezing-point of mercury

(-89° C.). But the toluene thermometers in use were old and good

instruments, so that the observations for this period may also be

regarded as perfectly reliable. Of course, all the thermometers had

been carefully examined at the Norwegian Meteorological Institute, and

at Framheim the freezing-point was regularly tested in melting snow.

The results show that the winter on the Barrier was about 19.°

C. (21.6° F.) colder than it usually is in McMurdo Sound, where

the British expeditions winter. The coldest month is August, with a

mean temperature of -44.5° C. (-48.1° F.); on fourteen days during

this month the temperature was below -50° C. (-58° F.). The lowest

temperature occurred on August 13: -58.5° C. (-73.3° F.); the warmest

day in that month had a temperature of -24° C. (-11.2° F.).

In October spring begins to approach, and in December the temperature

culminates with a mean for the month of -6.6° C. (+2O.l° F.), and a

highest maximum temperature of -0.2° C. (+31.6° F.). The temperature

was thus never above freezing-point, even in the warmest part of

the summer.

The daily course of the temperature -- warmest at noon and coldest

towards morning -- is, of course, not noticeable in winter, as the

sun is always below the horizon. But in April there is a sign of it,

and from September onward it is fairly marked, although the difference

between 2 p.m. and the mean of 8 a.m. and 8 p.m. only amounts to 2°

C. in the monthly mean.

Humidity of the Air.

For determining the relative humidity of the air the expedition

had two of Russeltvedt's torsion hygrometers. This instrument has

been accurately described in the Meteorologische Zeitschrift, 1908,

p. 396. It has the advantage that there are no axles or sockets to

be rusted or soiled, or filled with rime or drift-snow.

Fig. 1.

Fig. 2.

Fig. 3.

The two horsehairs (h, h') that are used, are stretched tight by a

torsion clamp (Z, Z', and L), which also carries the pointer; the

position of the pointer varies with the length of the hairs, which,

again, is dependent on the degree of humidity of the air. (See the

diagrams.) These instruments have been in use in Norway for several

years, especially at inland stations, where the winter is very cold,

and they have shown themselves superior to all others in accuracy and

durability; but there was no one on the Fram who knew anything about

them, and there is therefore a possibility that they were not always

in such good order as could be wished. On September 10, especially,

the variations are very remarkable; but on October 13 the second

instrument, No. 12, was hung out, and there can be no doubt of the

correctness of the subsequent observations.

It is seen that the relative humidity attains its maximum in winter,

in the months of July and August, with a mean of 90 per cent. The

driest air occurs in the spring month of November, with a mean of

73 per cent. The remaining months vary between 79 and 86 per cent.,

and the mean of the whole ten months is 82 per cent. The variations

quoted must be regarded as very small. On the other hand, the figures

themselves are very high, when the low temperatures are considered,

and this is doubtless the result of there being open water not very

far away. The daily course of humidity is contrary to the course of the

temperature, and does not show itself very markedly, except in January.

The absolute humidity, or partial pressure of aqueous vapour in the

air, expressed in millimetres in the height of the mercury in the

same way as the pressure of the atmosphere, follows in the main the

temperature of the air. The mean value for the whole period is only 0.8

millimetre (0.031 inch); December has the highest monthly mean with

2.5 millimetres (0.097 inch), August the lowest with 0.1 millimetre

(0.004 inch). The absolutely highest observation occurred on December

5 with 4.4 millimetres (0.173 inch), while the lowest of all is less

than 0.05 millimetre, and can therefore only be expressed by 0.0;

it occurred frequently in the course of the winter.

Precipitation.

Any attempt to measure the quantity of precipitation -- even

approximately -- had to be abandoned. Snowfall never occurred in

still weather, and in a wind there was always a drift that entirely

filled the gauge. On June 1 and 7 actual snowfall was observed,

but it was so insignificant that it could not be measured; it was,

however, composed of genuine flakes of snow. It sometimes happened

that precipitation of very small particles of ice was noticed;

these grains of ice can be seen against the observation lantern,

and heard on the observer's headgear; but on returning to the house,

nothing can be discovered on the clothing. Where the sign for snow

occurs in the column for Remarks, it means drift; these days are

included among days of precipitation. Sleet was observed only once,

in December. Rain never.

Cloudiness.

The figures indicate how many tenths of the visible heavens are covered

by clouds (or mist). No instrument is used in these observations;

they depend on personal estimate. They had to be abandoned during

the period of darkness, when it is difficult to see the sky.

Wind.

For measuring the velocity of the wind the expedition had a cup

and cross anemometer, which worked excellently the whole time. It

consists of a horizontal cross with a hollow hemisphere on each of

the four arms of the cross; the openings of the hemispheres are all

turned towards the same side of the cross-arms, and the cross can

revolve with a minimum of friction on a vertical axis at the point of

junction. The axis is connected with a recording mechanism, which is

set in motion at each observation and stopped after a lapse of half a

minute, when the figure is read off. This figure denotes the velocity

of the wind in metres per second, and is directly transferred to the

tables (here converted into feet per second).

The monthly means vary between 1.9 metres (6.2 feet) in May, and 5.5

metres (18 feet) in October; the mean for the whole ten months is 3.4

metres (11.1 feet) per second. These velocities may be characterized

as surprisingly small; and the number of stormy days agrees with

this low velocity. Their number for the whole period is only 11,

fairly evenly divided between the months; there are, however, five

stormy days in succession in the spring months October and November.

The frequency of the various directions of the wind has been added

up for each month, and gives the same characteristic distribution

throughout the whole period. As a mean we have the following table,

where the figures give the percentage of the total number of wind

observations:

N.E.

S.E.

S.W.

N.W.

Calm.

1.9

7.8

31.9

6.9

12.3

14.3

2.6

1.1

21.3

Almost every third direction is E., next to which come S.W. and S. Real

S.E., on the other hand, occurs comparatively rarely. Of N., N. W.,

and W. there is hardly anything. It may be interesting to see what

the distribution is when only high winds are taken into account --

that is, winds with a velocity of 10 metres (32.8 feet) per second

or more. We then have the following table of percentages:

N.E.

S.E.

S.W.

N.W.

Here again, E. is predominant, as half the high winds come from this

quarter. W. and N.W. together have only 6 per cent.

The total number of high winds is 51, or 5.6 per cent. of the total

of wind observations.

The most frequent directions of storms are also E. and N.E.

The Aurora Australis.

During the winter months auroral displays were frequently seen --

altogether on sixty-five days in six months, or an average of every

third day -- but for want of apparatus no exhaustive observations

could be attempted. The records are confined to brief notes of the

position of the aurora at the times of the three daily observations.

The frequency of the different directions, reckoned in percentages

of the total number of directions given, as for the wind, will be

found in the following table:

N.E.

S.E.

S.W.

N.W.

Zenith.

N. and N.E. are the most frequent, and together make up one-third of

all the directions recorded; but the nearest points on either side of

this maximum -- E. and N.W. -- are also very frequent, so that these

four points together -- N.W., N., N.E., E. -- have 64 per cent. of

the whole. The rarest direction is S.W., with only 3 per cent. (From

the position of the Magnetic Pole in relation to Framheim, one would

rather have expected E. to be the most frequent, and W. the rarest,

direction.) Probably the material before us is somewhat scanty for

establishing these directions.

Meteorological Record from Framheim.

April, 1911 -- January, 1912.

Height above sea-level, 36 feet. Gravity correction, .072 inch at

29.89 inches. Latitude, 78° 38' S. Longitude, 163° 37' W.

Explanation of Signs in the Tables.

SNOW signifies snow.

MIST ,, mist.

AURORA ,, aurora.

RINGSUN ,, large ring round the sun.

RINGMOON ,, ,, ,, moon.

STORM ,, storm

sq. ,, squalls

a. ,, a.m.

p. ,, p.m.

I., II, III., signify respectively 8 a.m., 2 p.m., and 8 p.m.

° (e.g., SNOW°) signifies slight.

2 (e.g., SNOW2) ,, heavy.

Times of day are always in local time.

The date was not changed on crossing the 180th meridian

CHAPTER III

Geology

Provisional Remarks on the Examination of the Geological Specimens

Brought by Roald Amundsen's South Polar Expedition from the Antarctic

Continent (South Victoria Land and King Edward VII. Land). By

J. Schetelig, Secretary of the Mineralogical Institute of Christiania

University

The collection of specimens of rocks brought back by Mr. Roald

Amundsen from his South Polar expedition has been sent by him to the

Mineralogical Institute of the University, the Director of which,

Professor W. C. Brögger, has been good enough to entrust to me the

work of examining this rare and valuable material, which gives us

information of the structure of hitherto untrodden regions.

Roald Amundsen himself brought back altogether about twenty specimens

of various kinds of rock from Mount Betty, which lies in lat. 85° 8'

S. Lieutenant Prestrud's expedition to King Edward VII. Land collected

in all about thirty specimens from Scott's Nunatak, which was the only

mountain bare of snow that this expedition met with on its route. A

number of the stones from Scott's Nunatak were brought away because

they were thickly overgrown with lichens. These specimens of lichens

have been sent to the Botanical Museum of the University.

A first cursory examination of the material was enough to show

that the specimens from Mount Betty and Scott's Nunatak consist

exclusively of granitic rocks and crystalline schists. There were

no specimens of sedimentary rocks which, by possibly containing

fossils, might have contributed to the determination of the age of

these mountains. Another thing that was immediately apparent was the

striking agreement that exists between the rocks from these two places,

lying so far apart. The distance from Mount Betty to Scott's Nunatak

is between seven and eight degrees of latitude.

I have examined the specimens microscopically.

From Mount Betty there are several specimens of white granite, with

dark and light mica; it has a great resemblance to the white granites

from Sogn, the Dovre district, and Nordland, in Norway. There is one

very beautiful specimen of shining white, fine-grained granite aplite,

with small, pale red garnets. These granites show in their exterior

no sign of pressure structure. The remaining rocks from Mount Betty

are gneissic granite, partly very rich in dark mica, and gneiss

(granitic schist); besides mica schist, with veins of quartz.

From Scott's Nunatak there are also several specimens of white granite,

very like those from Mount Betty. The remaining rocks from here are

richer in lime and iron, and show a series of gradual transitions

from micacious granite, through grano-diorite to quartz diorite,

with considerable quantities of dark mica, and green hornblende. In

one of the specimens the quantity of free quartz is so small that the

rock is almost a quartz-free diorite. The quartz diorites are: some

medium-grained, some coarse-grained (quartz-diorite-pegmatite), with

streaks of black mica. The schistose rocks from Scott's Nunatak are

streaked, and, in part, very fine-grained quartz diorite schists. Mica

schists do not occur among the specimens from this mountain.

Our knowledge of the geology of South Victoria Land is mainly due to

Scott's expedition of 1901 -- 1904, with H. T. Ferrar as geologist,

and Shackleton's expedition of 1907 -- 08, with Professor David

and R. Priestley as geologists. According to the investigations of

these expeditions, South Victoria Land consists of a vast, ancient

complex of crystalline schists and granitic rocks, large extents

of which are covered by a sandstone formation ("Beacon Sandstone,"

Ferrar), on the whole horizontally bedded, which is at least 1,500 feet

thick, and in which Shackleton found seams of coal and fossil wood (a

coniferous tree). This, as it belongs to the Upper Devonian or Lower

Carboniferous, determines a lower limit for the age of the sandstone

formation. Shackleton also found in lat. 85° 15' S. beds of limestone,

which he regards as underlying and being older than the sandstone. In

the limestone, which is also on the whole horizontally bedded,

only radiolaria have been found. The limestone is probably of older

Palæozoic age (? Silurian). It is, therefore, tolerably certain that

the underlying older formation of gneisses, crystalline schists and

granites, etc., is of Archæan age, and belongs to the foundation rocks.

Volcanic rocks are only found along the coast of Ross Sea and on

a range of islands parallel to the coast. Shackleton did not find

volcanic rocks on his ascent from the Barrier on his route towards

the South Pole.

G. T. Prior, who has described the rocks collected by Scott's

expedition, gives the following as belonging to the complex

of foundation rocks: gneisses, granites, diorites, banatites,

and other eruptive rocks, as well as crystalline limestone, with

chondrodite. Professor David and R. Priestley, the geologists of

Shackleton's expedition, refer to Ferrar's and Prior's description

of the foundation rocks, and state that according to their own

investigations the foundation rocks consist of banded gneiss, gneissic

granite, grano-diorite, and diorite rich in sphene, besides coarse

crystalline limestone as enclosures in the gneiss.

This list of the most important rocks belonging to the foundation

series of the parts of South Victoria Land already explored agrees so

closely with the rocks from Mount Betty and Scott's Nunatak, that there

can be no doubt that the latter also belong to the foundation rocks.

From the exhaustive investigations carried out by Scott's and

Shackleton's expeditions it appears that South Victoria Land is a

plateau land, consisting of a foundation platform, of great thickness

and prominence, above which lie remains, of greater or less extent,

of Palæozoic formations, horizontally bedded. From the specimens of

rock brought home by Roald Amundsen's expedition it is established that

the plateau of foundation rocks is continued eastward to Amundsen's

route to the South Pole, and that King Edward VII. Land is probably

a northern continuation, on the eastern side of Ross Sea, of the

foundation rock plateau of South Victoria Land.

Christiania,

September 26, 1912.

CHAPTER IV

The Astronomical Observations at the Pole

Note by Professor H. Geelmuyden

Christiania,

September 16, 1912.

When requested this summer to receive the astronomical observations

from Roald Amundsen's South Pole Expedition, for the purpose of working

them out, I at once put myself in communication with Mr. A. Alexander

(a mathematical master) to get him to undertake this work, while

indicating the manner in which the materials could be best dealt

with. As Mr. Alexander had in a very efficient manner participated in

the working out of the observations from Nansen's Fram Expedition,

and since then had calculated the astronomical observations from

Amundsen's Gjöa Expedition, and from Captain Isachsen's expeditions

to Spitzbergen, I knew by experience that he was not only a reliable

and painstaking calculator, but that he also has so full an insight

into the theoretical basis, that he is capable of working without

being bound down by instructions.

(Signed) H. Geelmuyden,

Professor of Astronomy,

The Observatory of the University,

Christiania.

Mr. Alexander's Report.

Captain Roald Amundsen,

At your request I shall here give briefly the result of my examination

of the observations from your South Pole Expedition. My calculations

are based on the longitude for Framheim given to me by Lieutenant

Prestrud, 163° 37' W. of Greenwich. He describes this longitude

as provisional, but only to such an extent that the final result

cannot differ appreciably from it. My own results may also be somewhat

modified on a final treatment of the material. But these modifications,

again, will only be immaterial, and, in any case, will not affect

the result of the investigations given below as to the position of

the two Polar stations.

At the first Polar station, on December 15, 1911, eighteen altitudes of

the sun were taken in all with each of the expedition's sextants. The

latitude calculated from these altitudes is, on an average of both

sextants, very near 89° 54', with a mean error of +-2'. The

longitude calculated from the altitudes is about

7t (105°) E.; but, as might be expected in this high latitude,

the aberrations are very considerable. We may, however, assume with

great certainty that this station lies between lat. 89° 52' and 89°

56' S., and between long. 90° and 120° E.

The variation of the compass at the first Polar station was determined

by a series of bearings of the sun. This gives us the absolute

direction of the last day's line of route. The length of this line

was measured as five and a half geographical miles. With the help of

this we are able to construct for Polheim a field of the same form

and extent as that within which the first Polar station must lie.

At Polheim, during a period of twenty-four hours (December 16 --

17), observations were taken every hour with one of the sextants. The

observations show an upper culmination altitude of 28° 19.2', and a

resulting lower culmination altitude of 23° 174'. These combining the

above two altitudes, an equal error on the same side in each will

have no influence on the result. The combination gives a latitude

of 89° 58.6'. That this result must be nearly correct is confirmed

by the considerable displacement of the periods of culmination

which is indicated by the series of observations, and which in the

immediate neighbourhood of the Pole is caused by the change in the

sun's declination. On the day of the observations this displacement

amounted to thirty minutes in 89° 57', forty-six minutes in 89° 58',

and over an hour and a half in 89° 59'. The upper culmination occurred

so much too late, and the lower culmination so much too early. The

interval between these two periods was thus diminished by double the

amount of the displacements given. Now the series of observations

shows that the interval between the upper and the lower culmination

amounted at the most to eleven hours; the displacement of the periods

of culmination was thus at least half an hour. It results that Polheim

must lie south of 89° 57', while at the same time we may assume that

it cannot lie south of 89° 59'. The moments of culmination could,

of course, only be determined very approximately, and in the same way

the observations as a whole are unserviceable for the determination

of longitude. It may, however, be stated with some certainty that

the longitude must be between 30° and 75° E. The latitude, as already

mentioned, is between 89° 57' and 89° 59', and the probable position

of Polheim may be given roughly as lat. 89° 58.5' S., and long. 60° E.

On the accompanying sketch-chart the letters abcd indicate the field

within which the first Polar station must lie; ABCD is the field which

is thereby assigned to Polheim; EFGH the field within which Polheim

must lie according to the observations taken on the spot itself; P

the probable position of Polheim, and L the resulting position of the

first Polar station. The position thus assigned to the latter agrees as

well as could be expected with the average result of the observations

of December 15. According to this, Polheim would be assumed to lie

one and a half geographical miles, or barely three kilometres, from

the South Pole, and certainly not so much as six kilometres from it.

From your verbal statement I learn that Helmer Hanssen and Bjaaland

walked four geographical miles from Polheim in the direction taken to

be south on the basis of the observations. On the chart the letters

efgh give the field within which the termination of their line of route

must lie. It will be seen from this that they passed the South Pole

at a distance which, on the one hand, can hardly have been so great

as two and a half kilometres, and on the other, hardly so great as two

kilometres; that, if the assumed position of Polheim be correct, they

passed the actual Pole at a distance of between 400 and 600 metres;

and that it is very probable that they passed the actual Pole at a

distance of a few hundred metres, perhaps even less.

I am, etc.,

(Signed) Anton Alexander.

Christiania,

September 22, 1912.

CHAPTER V

Oceanography

Remarks of the Oceanographical Investigation carried out by the "Fram"

in the North Atlantic in 1910 and in the South Atlantic in 1911. By

Professor Björn Helland-Hansen and Professor Fridtjof Nansen

In the earliest ages of the human race the sea formed an absolute

barrier. Men looked out upon its immense surface, now calm and

bright, now lashed by storms, and always mysteriously attractive;

but they could not grapple with it. Then they learned to make boats;

at first small, simple craft, which could only be used when the sea

was calm. But by degrees the boats were made larger and more perfect,

so that they could venture farther out and weather a storm if it

came. In antiquity the peoples of Europe accomplished the navigation

of the Mediterranean, and the boldest maritime nation was able to

sail round Africa and find the way to India by sea. Then came voyages

to the northern waters of Europe, and far back in the Middle Ages

enterprising seamen crossed from Norway to Iceland and Greenland and

the north-eastern part of North America. They sailed straight across

the North Atlantic, and were thus the true discoverers of that ocean.

Even in antiquity the Greek geographers had assumed that the greater

part of the globe was covered by sea, but it was not till the beginning

of the modern age that any at all accurate idea arose of the extent of

the earth's great masses of water. The knowledge of the ocean advanced

with more rapid steps than ever before. At first this knowledge

only extended to the surface, the comparative area of oceans, their

principal currents, and the general distribution of temperature. In

the middle of the last century Maury collected all that was known,

and drew charts of the currents and winds for the assistance of

navigation. This was the beginning of the scientific study of the

oceanic waters; at that time the conditions below the surface were

still little known. A few investigations, some of them valuable, had

been made of the sea fauna, even at great depths, but very little

had been done towards investigating the physical conditions. It

was seen, however, that there was here a great field for research,

and that there were great and important problems to be solved; and

then, half a century ago, the great scientific expeditions began,

which have brought an entire new world to our knowledge.

It is only forty years since the Challenger sailed on the first

great exploration of the oceans. Although during these forty years

a quantity of oceanographical observations has been collected with a

constant improvement of methods, it is, nevertheless, clear that our

knowledge of the ocean is still only in the preliminary stage. The

ocean has an area twice as great as that of the dry land, and it

occupies a space thirteen times as great as that occupied by the

land above sea-level. Apart from the great number of soundings for

depth alone, the number of oceanographical stations -- with a series

of physical and biological observations at various depths -- is very

small in proportion to the vast masses of water; and there are still

extensive regions of the ocean of the conditions of which we have

only a suspicion, but no certain knowledge. This applies also to the

Atlantic Ocean, and especially to the South Atlantic.

Scientific exploration of the ocean has several objects. It seeks to

explain the conditions governing a great and important part of our

earth, and to discover the laws that control the immense masses of

water in the ocean. It aims at acquiring a knowledge of its varied

fauna and flora, and of the relations between this infinity of

organisms and the medium in which they live. These were the principal

problems for the solution of which the voyage of the Challenger and

other scientific expeditions were undertaken. Maury's leading object

was to explain the conditions that are of practical importance to

navigation; his investigations were, in the first instance, applied

to utilitarian needs.

But the physical investigation of the ocean has yet another very

important bearing. The difference between a sea climate and a

continental climate has long been understood; it has long been known

that the sea has an equalizing effect on the temperature of the air,

so that in countries lying near the sea there is not so great a

difference between the heat of summer and the cold of winter as on

continents far from the sea-coast. It has also long been understood

that the warm currents produce a comparatively mild climate in high

latitudes, and that the cold currents coming from the Polar regions

produce a low temperature. It has been known for centuries that the

northern arm of the Gulf Stream makes Northern Europe as habitable

as it is, and that the Polar currents on the shores of Greenland and

Labrador prevent any richer development of civilization in these

regions. But it is only recently that modern investigation of the

ocean has begun to show the intimate interaction between sea and

air; an interaction which makes it probable that we shall be able to

forecast the main variations in climate from year to year, as soon

as we have a sufficiently large material in the shape of soundings.

In order to provide new oceanographical material by modern methods,

the plan of the Fram expedition included the making of a number of

investigations in the Atlantic Ocean. In June, 1910, the Fram went

on a trial cruise in the North Atlantic to the west of the British

Isles. Altogether twenty-five stations were taken in this region

during June and July before the Fram's final departure from Norway.

The expedition then went direct to the Antarctic and landed the shore

party on the Barrier. Neither on this trip nor on the Fram's subsequent

voyage to Buenos Aires were any investigations worth mentioning made,

as time was too short; but in June, 1911, Captain Nilsen took the

Fram on a cruise in the South Atlantic and made in all sixty valuable

stations along two lines between South America and Africa.

An exhaustive working out of the very considerable material collected

on these voyages has not yet been possible. We shall here only attempt

to set forth the most conspicuous results shown by a preliminary

examination.

Besides the meteorological observations and the collection of

plankton -- in fine silk tow-nets -- the investigations consisted

of taking temperatures and samples of water at different depths The

temperatures below the surface were ascertained by the best modern

reversing thermometers (Richter's); these thermometers are capable

of giving the temperature to within a few hundredths of a degree at

any depth. Samples of water were taken for the most part with Ekman's

reversing water-sampler; it consists of a brass tube, with a valve at

each end. When it is lowered the valves are open, so that the water

passes freely through the tube. When the apparatus has reached the

depth from which a sample is to be taken, a small slipping sinker

is sent down along the line. When the sinker strikes the sampler,

it displaces a small pin, which holds the brass tube in the position

in which the valves remain open. The tube then swings over, and this

closes the valves, so that the tube is filled with a hermetically

enclosed sample of water. These water samples were put into small

bottles, which were afterwards sent to Bergen, where the salinity of

each sample was determined. On the first cruise, in June and July,

1910, the observations on board were carried out by Mr. Adolf Schröer,

besides the permanent members of the expedition. The observations

in the South Atlantic in the following year were for the most part

carried out by Lieutenant Gjertsen and Kutschin.

The Atlantic Ocean is traversed by a series of main currents, which

are of great importance on account of their powerful influence

on the physical conditions of the surrounding regions of sea and

atmosphere. By its oceanographical investigations in 1910 and 1911

the Fram expedition has made important contributions to our knowledge

of many of these currents. We shall first speak of the investigations

in the North Atlantic in 1910, and afterwards of those in the South

Atlantic in 1911.

Investigations in the North Atlantic in June and July, 1910.

The waters of the Northern Atlantic Ocean, to the north of lats. 80°

and 40° N., are to a great extent in drifting motion north-eastward

and eastward from the American to the European side. This drift is

what is popularly called the Gulf Stream. To the west of the Bay

of Biscay the eastward flow of water divides into two branches, one

going south-eastward and southward, which is continued in the Canary

Current, and the other going north-eastward and northward outside

the British Isles, which sends comparatively warm streams of water

both in the direction of Iceland and past the Shetlands and Faroes

into the Norwegian Sea and north-eastward along the west coast of

Norway. This last arm of the Gulf Stream in the Norwegian Sea has

been well explored during the last ten or fifteen years; its course

and extent have been charted, and it has been shown to be subject to

great variations from year to year, which again appear to be closely

connected with variations in the development and habitat of several

important species of fish, such as cod, coal-fish, haddock, etc., as

well as with variations in the winter climate of Norway, the crops,

and other important conditions. By closely following the changes in

the Gulf Stream from year to year, it looks as if we should be able

to predict a long time in advance any great changes in the cod and

haddock fisheries in the North Sea, as well as variations in the

winter climate of North-Western Europe.

But the cause or causes of these variations in the Gulf Stream are at

present unknown. In order to solve this difficult question we must be

acquainted with the conditions in those regions of the Atlantic itself

through which this mighty ocean current flows, before it sends its

waters into the Norwegian Sea. But here we are met by the difficulty

that the investigations that have been made hitherto are extremely

inadequate and deficient; indeed, we have no accurate

(Fig. 1. -- Hypothetical Representation of the Surface Currents in

the Northern Atlantic in April.

After Nansen, in the Internationale Revue der gesamten Hydrobiologie

and Hydrographie, 1912.)

knowledge even of the course and extent of the current in this ocean. A

thorough investigation of it with the improved methods of our time

is therefore an inevitable necessity.

As the Gulf Stream is of so great importance to Northern Europe in

general, but especially to us Norwegians, it was not a mere accident

that three separate expeditions left Norway in the same year, 1910 --

Murray and Hjort's expedition in the Michael Sars, Amundsen's trial

trip in the Fram, and Nansen's voyage in the gunboat Frithjof --

all with the object of investigating the conditions in the North

Atlantic. The fact that on these three voyages observations were

made approximately at the same time in different parts of the

ocean increases their value in a great degree, since they can thus

be directly compared; we are thus able to obtain, for instance,

a reliable survey of the distribution of temperature and salinity,

and to draw important conclusions as to the extent of the currents

and the motion of the masses of water.

Amundsen's trial trip in the Fram and Nansen's voyage in the Frithjof

were made with the special object of studying the Gulf Stream in

the ocean to the west of the British Isles, and by the help of these

investigations it is now possible to chart the current and the extent

of the various volumes of water at different depths in this region

at that time.

A series of stations taken within the same region during Murray

and Hjort's expedition completes the survey, and provides valuable

material for comparison.

After sailing from Norway over the North Sea, the Fram passed through

the English Channel in June, 1910, and the first station was taken on

June 20, to the south of Ireland, in lat. 50° 50' N. and long. 10°

15' W., after which thirteen stations were taken to the westward,

to lat. 58° 16' N. and long. 17° 50' W., where the ship was on June

27. Her course then went in a northerly direction to lat. 57° 59'

N. and long. 15° 8' W., from which point a section of eleven stations

(Nos. 15 -- 25) was made straight across the Gulf Stream to the bank

on the north of Scotland, in lat. 59° 88' N. and long. 4° 44' W. The

voyage and the stations are represented in Fig. 2. Temperatures and

samples of water were taken at all the twenty-four stations at the

following depths: surface, 5, 10, 20, 30, 40, 50, 75, 100, 150, 200,

300, 400, and 500 metres (2.7, 5.4, 10.9, 16.3, 21.8, 27.2, 40.8,

54.5, 81.7, 109, 163.5, 218, and 272.5 fathoms) -- or less, where

the depth was not so great.

The Fram's southerly section, from Station 1 to 13 (see Fig. 3)

is divided into two parts at Station 10, on the Porcupine Bank,

south-west of Ireland. The eastern part, between Stations 1 and 10,

extends over to the bank south of Ireland, while the three stations

of the western part lie in the deep sea west of the Porcupine Bank.

[Fig. 2 and caption: Fig. 2. -- The "Fram's" Route from June 20

to July 7, 1910 (given in an unbroken line -- the figures denote

the stations).

The dotted line gives the Frithjof's route, and the squares give five

of the Michael Sars's stations.]

In both parts of this section there are, as shown in Fig. 3, two great

volumes of water, from the surface down to depths greater than 500

metres, which have salinities between 35.4 and 35.5 per mille. They

have also comparatively high temperatures; the isotherm for 10°

C. goes down to a depth of about 500 metres in both these parts.

It is obvious that both these comparatively salt and warm volumes

of water belong to the Gulf Stream. The more westerly of them, at

Stations 11 and 12, and in part 13, in the deep sea to the west of

the Porcupine Bank, is probably in motion towards the north-east

along the outside of this bank and then into Rockall Channel --

between Rockall Bank and the bank to the west of the

[Fig. 3 and caption: Fig. 3. -- Temperature and Salinity in the

"Fram's" Southern Section, June, 1910.]

British Isles -- where a corresponding volume of water, with a somewhat

lower salinity, is found again in the section which was taken a few

weeks later by the Frithjof from Ireland to the west-north-west

across the Rockall Bank. This volume of water has a special interest

for us, since, as will be mentioned later, it forms the main part

of that arm of the Gulf Stream which enters the Norwegian Sea, but

which is gradually cooled on its way and mixed with fresher water,

so that its salinity is constantly decreasing. This fresher water

is evidently derived in great measure directly from precipitation,

which is here in excess of the evaporation from the surface of the sea.

The volume of Gulf Stream water that is seen in the eastern part

(east of Station 10) of the southern Fram section, can only flow

north-eastward to a much less extent, as the Porcupine Bank is

connected with the bank to the west of Ireland by a submarine ridge

(with depths up to about 300 metres), which forms a great obstacle

to such a movement.

The two volumes of Gulf Stream water in the Fram's southern section of

1910 are divided by a volume of water, which lies over the Porcupine

Bank, and has a lower salinity and also a somewhat lower average

temperature. On the bank to the south of Ireland (Stations 1 and 2)

the salinity and average temperature are also comparatively low. The

fact that the water on the banks off the coast has lower salinities,

and in part lower temperatures, than the water outside in the deep sea,

has usually been explained by its being mixed with the coast water,

which is diluted with river water from the land. This explanation may

be correct in a great measure; but, of course, it will not apply to

the water over banks that lie out in the sea, far from any land. It

appears, nevertheless, on the Porcupine Bank, for instance, and,

as we shall see later, on the Rockall Bank, that the water on these

ocean banks is -- in any case in early summer -- colder and less salt

than the surrounding water of the sea. It appears from the Frithjof

section across the Rockall Bank, as well as from the two Fram sections,

that this must be due to precipitation combined with the vertical

currents near the surface, which are produced by the cooling of the

surface of the sea in the course of the winter. For, as the surface

water cools, it becomes heavier than the water immediately below,

and must then sink, while it is replaced by water from below. These

vertical currents extend deeper and deeper as the cooling proceeds in

the course of the winter, and bring about an almost equal temperature

and salinity in the upper waters of the sea during the winter, as far

down as this vertical circulation reaches. But as the precipitation

in these regions is constantly decreasing the salinity of the surface

water, this vertical circulation must bring about a diminution of

salinity in the underlying waters, with which the sinking surface

water is mixed into a homogeneous volume of water. The Frithjof

section in particular seems to show that the vertical circulation in

these regions reaches to a depth of 500 or 600 metres at the close

of the winter. If we consider, then, what must happen over a bank in

the ocean, where the depth is less than this, it is obvious that the

vertical circulation will here be prevented by the bottom from reaching

the depth it otherwise would, and there will be a smaller volume of

water to take part in this circulation and to be mixed with the cooled

and diluted surface water. But as the cooling of the surface and the

precipitation are the same there as in the surrounding regions, the

consequence must be that the whole of this volume of water over the

bank will be colder and less salt than the surrounding waters. And as

this bank water, on account of its lower temperature, is heavier than

the water of the surrounding sea, it will have a tendency to spread

itself outwards along the bottom, and to sink down along the slopes

from the sides of the bank. This obviously contributes to increase

the opposition that such banks offer to the advance of ocean currents,

even when they lie fairly deep.

These conditions, which in many respects are of great importance,

are clearly shown in the two Fram sections and the Frithjof section.

The Northern Fram section went from a point to the north-west of

the Rockall Bank (Station 15), across the northern end of this

bank (Station 16), and across the northern part of the wide channel

(Rockall Channel) between it and Scotland. As might be expected, both

temperature and salinity are lower in this section than in the southern

one, since in the course of their slow northward movement the waters

are cooled, especially by the vertical circulation in winter already

mentioned, and are mixed with water containing less salt, especially

precipitated water. While in the southern section the isotherm for

10° C. went down to 500 metres, it here lies at a depth of between

50 and 25 metres. In the comparatively short distance between the two

sections, the whole volume of water has been cooled between 1° and 2°

C. This represents a great quantity of warmth, and it is chiefly given

off to the air, which is thus warmed over a great area. Water contains

more than 3,000 times as much warmth as the same volume of air at the

same temperature. For example, if 1 cubic metre of water is cooled 1°,

and the whole quantity of warmth thus taken from the water is given

[Fig. 4. -- Temperature and Salinity in the "Fram's" Northern Section,

July 1910]

to the air, it is sufficient to warm more than 3,000 cubic metres of

air 1°, when subjected to the pressure of one atmosphere. In other

words, if the surface water of a region of the sea is cooled 1° to a

depth of 1 metre, the quantity of warmth thus taken from the sea is

sufficient to warm the air of the same region 1° up to a height of much

more than 3,000 metres, since at high altitudes the air is subjected

to less pressure, and consequently a cubic metre there contains

less air than at the sea-level. But it is not a depth of 1 metre of

the Gulf Stream that has been cooled 1° between these two sections;

it is a depth of about 500 metres or more, and it has been cooled

between 1° and 2° C. It will thus be easily understood that this loss

of warmth from the Gulf Stream must have a profound influence on the

temperature of the air over a wide area; we see how it comes about

that warm currents like this are capable of rendering the climate

of countries so much milder, as is the case in Europe; and we see

further how comparatively slight variations in the temperature of the

current from year to year must bring about considerable variations in

the climate; and how we must be in a position to predict these latter

changes when the temperature of the currents becomes the object of

extensive and continuous investigation. It may be hoped that this is

enough to show that far-reaching problems are here in question.

The salinity of the Gulf Stream water decreases considerably between

the Fram's southern and northern sections. While in the former it

was in great part between 35.4 and 35.5 per mille, in the latter it

is throughout not much more than 35.3 per mille. In this section,

also, the waters of the Gulf Stream are divided by an accumulation of

less salt and somewhat colder bank water, which here lies over the

Rockall Bank (Station 16). On the west side of this bank there is

again (Station 15) salter and warmer Gulf Stream water, though not

quite so warm as on the east. From the Frithjof section, a little

farther south, it appears that this western volume of Gulf Stream

water is comparatively small. The investigations of the Fram and the

Frithjof show that the part of the Gulf Stream which penetrates into

the Norwegian Sea comes in the main through the Rockall Channel,

between the Rockall Bank and the bank to the west of the British

Isles; its width in this region is thus considerably less than was

usually supposed. Evidently this is largely due to the influence of

the earth's rotation, whereby currents in the northern hemisphere are

deflected to the right, to a greater degree the farther north they

run. In this way the ocean currents, especially in northern latitudes,

are forced against banks and coasts lying to the right of them, and

frequently follow the edges, where the coast banks slope down to the

deep. The conclusion given above, that the Gulf Stream comes through

the Rockall Channel, is of importance to future investigations;

it shows that an annual investigation of the water of this channel

would certainly contribute in a valuable way to the understanding of

the variations of the climate of Western Europe.

We shall not dwell at greater length here on the results of the Fram's

oceanographical investigations in 1910. Only when the observations

then collected, as well as those of the Frithjof's and Michael Sars's

voyages, have been fully worked out shall we be able to make a complete

survey of what has been accomplished.

Investigations in the South Atlantic, June to August, 1911.

In the South Atlantic we have the southward Brazil Current on the

American side, and the northward Benguela Current on the African

side. In the southern part of the ocean there is a wide current flowing

from west to east in the west wind belt. And in its northern part,

immediately south of the Equator, the South Equatorial Current flows

from east to west. We have thus in the South Atlantic a vast circle of

currents, with a motion contrary to that of the hands of a clock. The

Fram expedition has now made two full sections across the central

part of the South Atlantic; these sections take in both the Brazil

Current and the Benguela Current, and they lie between the eastward

current on the south and the westward current on the north. This is

the first time that such complete sections have been obtained between

South America and Africa in this part of the ocean. And no doubt a

larger number of stations were taken on the Fram's voyage than have

been taken -- with the same amount of detail -- in the whole South

Atlantic by all previous expeditions put together.

When the Fram left Buenos Aires in June, 1911, the expedition went

eastward through the Brazil Current. The first station was taken

in lat. 36° 18' S. and long. 43° 15' W.; this was on June 17. Her

course was then north-east or east until Station 32 in lat. 20° 30'

S. and long. 8° 10' E.; this station lay in the Benguela Current,

about 800 miles from the coast of Africa, and it was taken on July

22. From there she went in a gentle curve

[Fig. 5 and caption]

past St. Helena and Trinidad back to America. The last station (No. 60)

was taken on August 19 in the Brazil Current in lat. 24° 39' S. and

about long. 40° W.; this station lay about 200 miles south-east of

Rio de Janeiro.

There was an average distance of 100 nautical miles between one station

and the next. At nearly all the stations investigations were made at

the following depths: surface, 5, 10, 25, 50, 100, 150, 200, 250,

300, 400, 500, 750, and 1,000 metres (2.7, 5.4, 13.6, 27.2, 54.5,

81.7, 109, 136.2, 163.5, 218, 272.5, and 545 fathoms). At one or two

of the stations observations were also taken at 1,500 and 2,000 metres

(817.5 and 1,090 fathoms).

The investigations were thus carried out from about the middle of

July to the middle of August, in that part of the southern winter

which corresponds to the period between the middle of

[Fig. 6]

Fig. 6. -- Currents in the South Atlantic (June -- August, 1911).

December and the middle of February in the northern hemisphere We must

first see what the conditions were on the surface in those regions

in the middle of the winter of 1911.

It must be remembered that the currents on the two sides of the

ocean flow in opposite directions. Along the coast of Africa, we have

the Benguela Current, flowing from south to north; on the American

side the Brazil Current flows from the tropics southward. The former

current is therefore comparatively cold and the latter comparatively

warm. This is clearly seen on the chart, which shows the distribution

of temperatures and salinities on the surface. In lat. 20° S. it

was only about 17° C. off the African coast, while it was about 23°

C. off the coast of Brazil.

The salinity depends on the relation between evaporation and the

addition of fresh water. The Benguela Current comes from

[Fig. 7]

Fig. 7. -- Salinities and Temperatures at the Surface in the South

Atlantic (June -- August, 1911) regions where the salinity is

comparatively low; this is due to the acquisition of fresh water in

the Antarctic Ocean, where the evaporation from the surface is small

and the precipitation comparatively large. A part of this fresh water

is also acquired by the sea in the form of icebergs from the Antarctic

Continent. These icebergs melt as they drift about the sea.

Immediately off the African coast there is a belt where the salinity is

under 35 per mille on the surface; farther out in the Benguela Current

the salinity is for the most part between 35 and 36 per mille. As the

water is carried northward by the current, evaporation becomes greater

and greater; the air becomes comparatively warm and dry. Thereby the

salinity is raised. The Benguela Current is then continued westward in

the South Equatorial Current; a part of this afterwards turns to the

north-west, and crosses the Equator into the North Atlantic, where it

joins the North Equatorial Current. This part must thus pass through

the belt of calms in the tropics. In this region falls of rain occur,

heavy enough to decrease the surface salinity again. But the other part

of the South Equatorial Current turns southward along the coast of

Brazil, and is then given the name of the Brazil Current. The volume

of water that passes this way receives at first only small additions

of precipitation; the air is so dry and warm in this region that

the salinity on the surface rises to over 37 per mille. This will

be clearly seen on the chart; the saltest water in the whole South

Atlantic is found in the northern part of the Brazil Current. Farther

to the south in this current the salinity decreases again, as

the water is there mixed with fresher water from the South. The

River La Plata sends out enormous quantities of fresh water into

the ocean. Most of this goes northward, on account of the earth's

rotation; the effect of this is, of course, to deflect the currents

of the southern hemisphere to the left, and those of the northern

hemisphere to the right. Besides the water from the River La Plata,

there is a current flowing northward along the coast of Patagonia --

namely, the Falkland Current. Like the Benguela Current, it brings

water with lower salinities than those of the waters farther north;

therefore, in proportion as the salt water of the Brazil Current

is mixed with the water from the River La Plata and the Falkland

Current, its salinity decreases. These various conditions give the

explanation of the distribution of salinity and temperature that is

seen in the chart.

Between the two long lines of section there is a distance of

between ten and fifteen degrees of latitude. There is, therefore,

a considerable difference in temperature. In the southern section

the average surface temperature at Stations 1 to 26 (June 17 to

July 17) was 17.9° C.; in the northern section at Stations 36 to 60

(July 26 to August 19) it was 21.6° C. There was thus a difference

of 3.7° C. If all the stations had been taken simultaneously, the

difference would have been somewhat greater; the northern section

was, of course, taken later in the winter, and the temperatures were

therefore proportionally lower than in the southern section. The

difference corresponds fairly accurately with that which Kr:ummel

has calculated from previous observations.

We must now look at the conditions below the surface in that part of

the South Atlantic which was investigated by the Fram Expedition.

The observations show in the first place that both temperatures and

salinities at every one of the stations give the same values from

the surface downward to somewhere between 75 and 150 metres (40.8 and

81.7 fathoms). This equalization of temperature and salinity is due to

the vertical currents produced by cooling in winter; we shall return

to it later. But below these depths the temperatures and salinities

decrease rather rapidly for some distance.

The conditions of temperature at 400 metres (218 fathoms) below the

surface are shown in the next little chart. This chart is based on

the Fram Expedition, and, as regards the other parts of the ocean, on

Schott's comparison of the results of previous expeditions. It will

be seen that the Fram's observations agree very well with previous

soundings, but are much more detailed.

The chart shows clearly that it is much warmer at 400 metres (218

fathoms) in the central part of the South Atlantic than either farther

north -- nearer the Equator -- or farther south. On the Equator

there is a fairly large area where the temperature is only 7° or 8°

C. at 400 metres, whereas in lats. 2O° to 30° S. there are large

regions where it is above 12° C.; sometimes above 13° C., or even

14°C. South of lat. 30° S. the temperature decreases again rapidly;

in the chart no lines are drawn for temperatures below 8° C., as we

have not sufficient observations to show the course of these lines

properly. But we know that the temperature at 400 metres sinks to

about 0° C. in the Antarctic Ocean.

[Fig. 8]

Fig. 8. -- Temperatures (Centigrade) at a Depth of 400 Metres

(218 Fathoms).

At these depths, then, we find the warmest water within the region

investigated by the Fram. If we now compare the distribution of

temperature at 400 metres with the chart of currents in the South

Atlantic, we see that the warm region lies in the centre of the great

circulation of which mention was made above. We see that there are

high temperatures on the left-hand side of the currents, and low on the

right-hand side. This, again, is an effect of the earth's rotation, for

the high temperatures mean as a rule that the water is comparatively

light, and the low that it is comparatively heavy. Now, the effect

of the earth's rotation in the southern hemisphere is that the light

(warm) water from above is forced somewhat down on the left-hand side

of the current, and that the heavy (cold) water from below is raised

somewhat. In the northern hemisphere the contrary is the case. This

explains the cold water at a depth of 400 metres on the Equator; it

also explains the fact that the water immediately off the coasts of

Africa and South America is considerably colder than farther out in the

ocean. We now have data for studying the relation between the currents

and the distribution of warmth in the volumes of water in a way which

affords valuable information as to the movements themselves. The

material collected by the Fram will doubtless be of considerable

importance in this way when it has been finally worked out.

Below 400 metres (218 fathoms) the temperature further decreases

everywhere in the South Atlantic, at first rapidly to a depth

between 500 and 1,000 metres (272.5 and 545 fathoms), afterwards very

slowly. It is possible, however, that at the greatest depths it rises

a little again, but this will only be a question of hundredths, or,

in any case, very few tenths of a degree.

It is known from previous investigations in the South Atlantic, that

the waters at the greatest depths, several thousand metres below the

surface, have a temperature of between 0° and 3° C. Along the whole

Atlantic, from the extreme north (near Iceland) to the extreme south,

there runs a ridge about half-way between Europe and Africa on the

one side, and the two American continents on the other. A little

to the north of the Equator there is a slight elevation across the

ocean floor between South America and Africa. Farther south (between

lats. 25° and 35° S.) another irregular ridge runs across between these

continents. We therefore have four deep regions in the South Atlantic,

two on the west (the Brazilian Deep and the Argentine Deep) and two

on the east (the West African Deep and the South African Deep). Now

it has been found that the "bottom water" in these great deeps -- the

bottom lies more than 5,000 metres (2,725 fathoms) below the surface --

is not always the same. In the two western deeps, off South America,

the temperature is only a little above 0° C. We find about the same

temperatures in the South African Deep, and farther eastward in a

belt that is continued round the whole earth. To the south, between

this belt and Antarctica, the temperature of the great deeps is much

lower, below 0° C. But in the West African Deep the temperature is

about 2° C. higher; we find there the same temperatures of between 2°

and 2.5° C. as are found everywhere in the deepest parts of the North

Atlantic. The explanation of this must be that the bottom water in

the western part of the South Atlantic comes from the south, while

in the north-eastern part it comes from the north. This is connected

with the earth's rotation, which has a tendency to deflect currents

to the left in the southern hemisphere. The bottom water coming from

the south goes to the left -- that is, to the South American side;

that which comes from the north also goes to the left -- that is,

to the African side.

The salinity also decreases from the surface downward to 600 to 800

metres (about 300 to 400 fathoms), where it is only a little over

34 per mille, but under 34.5 per mille; lower down it rises to about

34.7 per mille in the bottom water that comes from the south, and to

about 34.9 per mille in that which comes from the North Atlantic.

We mentioned that the Benguela Current is colder and less salt at the

surface than the Brazil Current. The same thing is found in those parts

of the currents that lie below the surface. This is clearly shown in

Fig. 9, which gives the distribution of temperature at Station 32 in

the Benguela Current, and at Station 60 in the Brazil Current; at the

various depths down to 500 metres (272.5 fathoms) it was between 5°

and 7° C. colder in the former than in the latter. Deeper down the

difference becomes less, and at 1,000 metres (545 fathoms) there was

only a difference of one or two tenths of a degree.

Fig. 10 shows a corresponding difference in salinities; in the first

200 metres below the surface the water was about

[Fig. 9.]

Fig. 9. -- Temperatures at Station 32 (In the Benguela Current, July

22, 1911), and at Station 6O (In the Brazil Current, August 19, 1911).

1 per mille more saline in the Brazil Current than in the Benguela

Current. Both these currents are confined to the upper waters;

the former probably goes down to a depth of about 1,000 metres (545

fathoms), while the latter does not reach a depth of much more than 500

metres. Below the two currents the conditions are fairly homogeneous,

and there is no difference worth mentioning in the salinities.

The conditions between the surface and a depth of 1,000 metres along

the two main lines of course are clearly shown in the two sections

(Figs. 11 and l2). In these the isotherms for every second degree are

drawn in broken lines. Lines connecting points with the same salinity

(isohalins) are drawn unbroken, and, in addition, salinities above

35 per mille are shown by shading. Above is a series of figures,

giving the numbers of the stations. To understand

[Fig. 10 and caption]

the sections rightly it must be borne in mind that the vertical scale

is 2,000 times greater than the horizontal.

Many of the conditions we have already mentioned are clearly apparent

in the sections: the small variations between the surface and a depth

of about 100 metres at each station; the decrease of temperature and

salinity as the depth increases; the high values both of temperature

and salinity in the western part as compared with the eastern. We

see from the sections how nearly the isotherms and isohalins follow

each other. Thus, where the temperature is 12° C., the water almost

invariably has a salinity very near 35 per mille. This water at 12°

C., with a salinity of 35 per mille, is found in the western part

of the area (in the Brazil Current) at a depth of 500 to 600 metres,

but in the eastern part (in the Benguela Current) no deeper than 200

to 250 metres (109 to 136 fathoms).

We see further in both sections, and especially in the southern one,

that the isotherms and isohalins often have an undulating course,

since the conditions at one station may be different from those at the

neighbouring stations. To point to one or two examples: at Station 19

the water a few hundred metres down was comparatively warm; it was,

for instance, 12° C. at about 470 metres (256 fathoms) at this station;

while the same temperature was found at about 340 metres (185 fathoms)

at both the neighbouring stations, 18 and 20. At Station 2 it was

relatively cold, as cold as it was a few hundred metres deeper down

at Stations 1 and 3.

These undulating curves of the isotherms and isohalins are familiar to

us in the Norwegian Sea, where they have been shown in most sections

taken in recent years. They may be explained in more than one way. They

may be due to actual waves, which are transmitted through the central

waters of the sea. Many things go to show that such waves may actually

occur far below the surface, in which case they must attain great

dimensions; they must, indeed, be more than 100 metres high at times,

and yet -- fortunately -- they are not felt on the surface. In the

Norwegian Sea we have frequently found these wave-like rises and

falls. Or the curves may be due to differences in the rapidity and

direction of the currents. Here the earth's rotation comes into play,

since, as mentioned above, it causes zones of water to be depressed

on one side and raised on the other; and the degree of force with

which this takes place is dependent on the rapidity of the current

and on the geographical latitude. The effect is slight in the tropics,

but great in high latitudes. This, so far as it goes, agrees with the

[Fig. 11 and captions]

fact that the curves of the isotherms and isohalins are more marked

in the more southerly of our two sections than in the more northerly

one, which lies 10 or 15 degrees nearer the Equator.

But the probability is that the curves are due to the formation of

eddies in the currents. In an eddy the light and warm water will be

depressed to greater depths if the eddy goes contrary to the hands

of a clock and is situated in the southern hemisphere. We appear to

have such an eddy around Station 19, for example. Around Station 2 an

eddy appears to be going the other way; that is, the same way as the

hands of a clock. On the chart of currents we have indicated some of

these eddies from the observations of the distribution of salinity

and temperature made by the Fram Expedition.

While this, then, is the probable explanation of the irregularities

shown by the lines of the sections, it is not impossible that they

may be due to other conditions, such as, for instance, the submarine

waves alluded to above. Another possibility is that they may be a

consequence of variations in the rapidity of the current, produced,

for instance, by wind. The periodical variations caused by the tides

will hardly be an adequate explanation of what happens here, although

during Murray and Hjort's Atlantic Expedition in the Michael Sars (in

1910), and recently during Nansen's voyage to the Arctic Ocean in the

Veslemöy (in 1912), the existence of tidal currents in the open ocean

was proved. It may be hoped that the further examination of the Fram

material will make these matters clearer. But however this may be, it

is interesting to establish the fact that in so great and deep an ocean

as the South Atlantic very considerable variations of this kind may

occur between points which lie near together and in the same current.

As we have already mentioned in passing, the observations show that

the same temperatures and salinities as are found at the surface are

continued downward almost unchanged to a depth of between 75 and 150

metres; on an average it is about 100 metres. This is a typical winter

condition, and is due to the vertical circulation already mentioned,

which is caused by the surface water being cooled in winter,

thus becoming heavier than the water below, so that it must sink

and give place to lighter water which rises. In this way the upper

zones of water become mixed, and acquire almost equal temperatures

and salinities. It thus appears that the vertical currents reached a

depth of about 100 metres in July, 1911, in the central part of the

South Atlantic. This cooling of the water is a gain to the air, and

what happens is that not only the surface gives off warmth to the air,

but also the sub-surface waters, to as great a depth as is reached by

the vertical circulation. This makes it a question of enormous values.

This state of things is clearly apparent in the sections, where

the isotherms and isohalins run vertically for some way below

the surface. It is also clearly seen when we draw the curves of

distribution of salinity and temperature at the different stations, as

we have done in the two diagrams for Stations 32 and 60 (Fig. 9). The

temperatures had fallen several degrees at the surface at the time

the Fram's investigations were made. And if we are to judge from the

general appearance of the station curves, and from the form they

usually assume in summer in these regions, we shall arrive at the

conclusion that the whole volume of water from the surface down to

a depth of 100 metres must be cooled on an average about 2° C.

As already pointed out, a simple calculation gives the following:

if a cubic metre of water is cooled 1° C., and the whole quantity

of warmth thus taken from the water is given to the air, it will be

sufficient to warm more than 3,000 cubic metres of air 1° C. A few

figures will give an impression of what this means. The region lying

between lats. 15° and 35° S. and between South America and Africa --

roughly speaking, the region investigated by the Fram Expedition --

has an area of 13,000,000 square kilometres. We may now assume that

this part of the ocean gave off so much warmth to the air that a

zone of water 100 metres in depth was thereby cooled on an average 2°

C. This zone of water weighs about 1.5 trillion kilogrammes, and the

quantity of warmth given off thus corresponds to about 2.5 trillion

great calories.

It has been calculated that the whole atmosphere of the earth

weighs 5.27 trillion kilogrammes, and it will require something

over 1 trillion great calories to warm the whole of this mass of

air 1°C. From this it follows that the quantity of warmth which,

according to our calculation, is given off to the air from that part

of the South Atlantic lying between lats. 15° and 35° S., will be

sufficient to warm the whole atmosphere of the earth about 2° C., and

this is only a comparatively small part of the ocean. These figures

give one a powerful impression of the important part played by the

sea in relation to the air. The sea stores up warmth when it absorbs

the rays of the sun; it gives off warmth again when the cold season

comes. We may compare it with earthenware stoves, which continue to

warm our rooms long after the fire in them has gone out. In a similar

way the sea keeps the earth warm long after summer has gone and the

sun's rays have lost their power.

Now it is a familiar fact that the average temperature of the air for

the whole year is a little lower than that of the sea; in winter it

is, as a rule, considerably lower. The sea endeavours to raise the

temperature of the air; therefore, the warmer the sea is, the higher

the temperature of the air will rise. It is not surprising, then,

that after several years' investigations in the Norwegian Sea we

have found that the winter in Northern Europe is milder than usual

when the water of the Norwegian Sea contains more than the average

amount of warmth. This is perfectly natural. But we ought now to be

able to go a step farther and say beforehand whether the winter air

will be warmer or colder than the normal after determining the amount

of warmth in the sea.

It has thus been shown that the amount of warmth in that part of the

ocean which we call the Norwegian Sea varies from year to year. It

was shown by the Atlantic Expedition of the Michael Sars in 1910 that

the central part of the North Atlantic was considerably colder in 1910

than in 1873, when the Challenger Expedition made investigations there;

but the temperatures in 1910

[Fig. 13]

Fig. 13. -- Temperatures at one of the "Fram's" and one of the

"Challenger's" Stations, to the South of the South Equatorial Current

were about the same as those of 1876, when the Challenger was on her

way back to England.

We can now make similar comparisons as regards the South Atlantic. In

1876 the Challenger took a number of stations in about the same region

as was investigated by the Fram. The Challenger's Station 339 at the

end of March, 1876, lies near the point where the Fram's Station 44

was taken at the beginning of August, 1911. Both these stations lay in

about lat. 17.5° S., approximately half-way between Africa and South

America -- that is, in the region where a relatively slack current

runs westward, to the south of the South Equatorial Current. We

can note the difference in Fig. 13, which shows the distribution

of temperature at the two stations. The Challenger's station was

taken during the autumn and the Fram's during the winter. It was

therefore over 3° C. warmer at the surface in March, 1876, than in

August, 1911. The curve for the Challenger station shows the usual

distribution of temperature immediately below the surface in summer;

the temperature falls constantly from the surface downward. At the

Fram's station we see the typical winter conditions; we there find the

same temperature from the surface to a depth of 100 metres, on account

of cooling and vertical circulation. In summer, at the beginning of

the year 1911, the temperature curve for the Fram's station would

have taken about the same form as the other curve; but it would have

shown higher temperatures, as it does in the deeper zones, from 100

metres down to about 500 metres. For we see that in these zones it

was throughout 1° C. or so warmer in 1911 than in 1876; that is to

say, there was a much greater store of warmth in this part of the

ocean in 1911 than in 1876. May not the result of this have been

that the air in this region, and also in the east of South America

and the west of Africa, was warmer during the winter of 1911 than

during that of 1876? We have not sufficient data to be able to say

with certainty whether this difference in the amount of warmth in the

two years applied generally to the whole ocean, or only to that part

which surrounds the position of the station; but if it was general,

we ought probably to be able to find a corresponding difference in

the climate of the neighbouring regions. Between 500 and 800 metres

(272 and 486 fathoms) the temperatures were exactly the same in

both years, and at 900 and 1,000 metres (490 and 545 fathoms) there

was only a difference of two or three tenths of a degree. In these

deeper parts of the ocean the conditions are probably very similar;

we have there no variations worth mentioning, because the warming of

the surface and sub-surface waters by the sun has no effect there,

unless, indeed, the currents at these depths may vary so

[Fig. 14]

Fig. 14. -- Temperatures at one of the "Fram's" and one of the

"Valdivia's" Stations, in the Benguela Current. Much that there may

be a warm current one year and a cold one another year. But this is

improbable out in the middle of the ocean.

In the neighbourhood of the African coast, on the other hand, it looks

as if there may be considerable variations even in the deeper zones

below 500 metres (272 fathoms). During the Valdivia Expedition in 1898

a station (No. 82) was taken in the Benguela Current in the middle of

October, not far from the point at which the Fram's Station 31 lay. The

temperature curves from here show that it was much warmer (over 1.5°

C.) in 1898 than in 1911 in the zones between 500 and 800 metres

(272 and 486 fathoms). Probably the currents may vary considerably

here. But in the upper waters of the Benguela Current itself, from the

surface down to 150 metres, it was considerably warmer in 1911 than

in 1898; this difference corresponds to that which we found in the

previous comparison of the Challenger's and Fram's stations of 1876

and 1911. Between 200 and 400 metres (109 and 218 fathoms) there was

no difference between 1898 and 1911; nor was there at 1,000 metres

(545 fathoms).

In 1906 some investigations of the eastern part of the South Atlantic

were conducted by the Planet. In the middle of March a station was

taken (No. 25) not far from St. Helena and in the neighbourhood of the

Fram's Station 39, at the end of July, 1911. Here, also, we find great

variations; it was much warmer in 1911 than in 1906, apart from the

winter cooling by vertical circulation of the sub-surface waters. At

a depth of only 100 metres (54.5 fathoms) it was 2° C. warmer in 1911

than in 1906; at 400 metres (218 fathoms) the difference was over 1°,

and even at 800 metres (486 fathoms) it was about 0.75° C. warmer in

1911 than in 1906. At 1,000 metres (545 fathoms) the difference was

only 0.3°.

From the Planet's station we also have problems of salinity,

determined by modern methods. It appears that the salinities at the

Planet station, in any case to a depth of 400 metres, were lower, and

in part much lower, than those of the Fram Expedition. At 100 metres

the difference was even greater than 0.5 per mille; this is a great

deal in the same region of open sea. Now, it must be remembered that

the current in the neighbourhood of St. Helena may be regarded as a

continuation of the Benguela Current, which comes from the south and

has relatively low salinities. It looks, therefore, as if there were

yearly variations of salinity in these

[Fig. 15]

Fig. 15. -- Temperatures at the "Planet's" Station 25, and the "Fram's"

Station 39 -- Both in the Neighbourhood of St. Helena

[Fig. 16]

Fig. 16. -- Salinities at the "Planet's" Station 25 (March 19, 1906)

And the "Fram's" Station 39 (July 29, 1911).

regions. This may either be due to corresponding variations in the

Benguela Current -- partly because the relation between

precipitation and evaporation may vary in different years, and partly

because there may be variations in the acquisition of less saline

water from the Antarctic Ocean. Or it may be due to the

Benguela Current in the neighbourhood of St. Helena having

a larger admixture of the warm and salt water to the west of it in

one year than in another. In either case we may expect a

relatively low salinity (as in 1906 as compared with 1911) to be

accompanied by a relatively low temperature, such as we have

found by a comparison of the Planet's observations with those of

the Fram.

We require a larger and more complete material for comparison; but even

that which is here referred to shows that there may be considerable

yearly variations both in the important, relatively cold Benguela

Current, and in the currents in other parts of the South Atlantic. It

is a substantial result of the observations made on the Fram's voyage

that they give us an idea of great annual variations in so important a

region as the South Atlantic Ocean. When the whole material has been

further examined it will be seen whether it may also contribute to

an understanding of the climatic conditions of the nearest countries,

where there is a large population, and where, in consequence, a more

accurate knowledge of the variations of climate will have more than

a mere scientific interest.

NOTES

[1] -- Fram means "forward," "out of," "through." -- Tr.

[2] -- This retrospective chapter has here been greatly condensed, as

the ground is already covered, for English readers, by Dr. H. R. Mill's

"The Siege of the South Pole," Sir Ernest Shackleton's "The Heart of

the Antarctic," and other works. -- Tr.

[3] -- Anniversary of the dissolution of the Union with Sweden. -- Tr.

[4] -- Daengealso means "thrash." -- Tr.

[5] -- Unless otherwise stated, "miles" means English statute

miles. -- Tr.

[6] -- A language based on that of the country districts, as opposed

to the literary language, which is practically the same as Danish. The

maal is more closely related to Old Norse. -- Tr.

[7] -- Named after Dr. Nansen's daughter. -- Tr.

[8] -- A vessel sailing continuously to the eastward puts the clock

on every day, one hour for every fifteen degrees of longitude; one

sailing westward puts it back in the same way. In long. 180deg. one

of them has gone twelve hours forward, the other twelve hours back;

the difference is thus twenty-four hours. In changing the longitude,

therefore, one has to change the date, so that, in passing from east

to west longitude, one will have the same day twice over, and in

passing from west to east longitude a day must be missed.

[9] -- For the benefit of those who know what a buntline on a sail is,

I may remark that besides the usual topsail buntlines we had six extra

buntlines round the whole sail, so that when it was clewed up it was,

so to speak, made fast. We got the sail clewed up without its going to

pieces, but it took us over an hour. We had to take this precaution,

of having so many buntlines, as we were short-handed.

End of Project Gutenberg's The South Pole, Volumes 1 and 2, by Roald Amundsen

The South Pole; an account of the Norwegian Antarctic expedition in the "Fram," 1910-12 — Volume 1 and Volume 2 · 第 17 / 17 章

Extraordinary precautions were taken for strengthening the ship's