V

Tasmanian Field Naturalists’ Club

1924-1925

OFFICE-BEARERS

Chairman:

DR. W. L. CROWTHER, D.S.O., M.B.

Vice-Chairman:

MR. J. REYNOLDS.

Hon. Secretary:

MR. CLIVE LORD,

Tasmanian Museum.

Hon. Assistant Secretary:

MR. J. C. BREADEN,

Waverley Avenue, New Town.

Committee:

MESSRS. L. RODWAY, C.M.G.; A. N. LEWIS, M.C., LL.B.;
M. S. R. SHARLAND; A. R. REID; G. B. DAVIES.

Hon. Auditor:

MR. C. W. ROBERTS.

%\)e Tasmanian naturalist

THE JOURNAL OF THE

Tasmanian Field Naturalists’ Club

New Series—Vol. I. JULY, 1925 No. III.

Outlines of Tasmanian Geology

SECTION 13 (Continued)
UNDERGROUND WATER.

Before we discuss the forms of land
surface that can be moulded through the
action of rivers, we must mention brief¬
ly the great factor controlling the con¬
tinual flow of a river. A certain amount
of the water runs off the landscape after
falls of rain and finds its way down the
lowest valley; but rainfall .is not neces¬
sarily regular, and most large rivers flow
with relatively little alteration through
the driest summer. Most of this water
has not run directly off the sides of the
valley, but has come as soakage or
springs from below the surface.

Most of the rain that falls on the
surface soaks down through the soil and
rocks. Beneath the surface, at varying
depths, the rocks are more or less satur¬
ated. If a well is sunk into this zone
it will be filled with water up to the
level of the top of the saturated zone.
The top of this belt is called the water
table, and it conforms roughly with the
configuration of the surface. Its posi¬
tion depends largely on rainfall, and also
on the nature of the country and slope
of the strata, while some compact rocks
are so dense that they absorb little or
no water at all. Our diabase (or blue
metal) is of this nature.

Travels of Water Underground.

Water percolates through the substance
of previous rocks, such as gravels and
such loosely compacted rocks and sand¬
stones, and other soft rocks. It
finds its way in crncks and
pores of harder rocks. Some
very compact rocks, such as granite, have
few cracks at any distance from the
surface, and others, such as day, are
formed of fine particle* which fit very
closely together. These types of rocks
form an absolute bar to the travels of
water underground. But with the ex¬

ception, perhaps, of clay, there are usu¬
ally cracks, joints, strata planes, and
crushed zones even in the hardest rock
through which water can penetrate, and
any large bed of clay usually has many
inclusions of pervious sands.

Through these pervious rocks water
descends from the surface, and if the
surface supply is sufficient the bed of
rock will eventually become saturated
(that is. will contain as much water as
it can hold). When this occurs the
water table will gradually rise. If the
particular bed of rock is surrounded by
impervious strata the water will rise,
perhaps, to the surface, or at any rate
until it reaches the broken surface zone
of some neighboring rock; and it will
then pass along the top of the impervi¬
ous bed. But it usually happens that
beds of porous rock are morq, or less
connected. Water in that case passes
from one to another, and the water ta¬
ble maintains an approximate level below
the surface throughout a district, just as
the level of inter-connected lakes re¬
mains much the same.

The Water Table.

Therefore, unless the rock is abso¬
lutely impervious, at some distance be¬
low the surface water will be struck. The
quantity and depth depend on — (l)Pre-
cipitation; (2) relative amount of space
in rock for storage (which depends
largely on the nature of the rock); and
(3) the possibility of getaway for the
water underground. The level the water
table stands at is known as the ground
water level. Naturally, in regions of
heavy rainfall, this is near the surface,
and in deserts it is at a considerable
depth. In relatively i>ervious rocks,

such as sandstone, the water table is con¬
stant throughout the bed, and a well
sunk to it anywhere will^ yield water.
In other rocks, such as diabase, it will
exist only in more porous pockets. This

a)

THE TASMANIAN NATURALIST

ground water level follows roughly the
contour of the surface, and hence water
inay be found on the tops of ridges as in
the bottom of valleys. In Tasmania,
on the wet West Coast, water can be
struck in all but the very solid rocks ac
a very shallow depth. At Catamaran
pits sunk for .six feet soon fill with water
and remain with water within a few
feet of the surface throughout the year.
On the button grass plains, which are
usually underlain at some depth or
other by clay, water can be struck with¬
in a few feet of the surface, and this
even on the top of steep hills. Further
east the ground water level sinks, but
there are few places wherein gravel or
standstonee water will not be struck be¬
fore the fifty feet level is reached. Thus
all mines have to be kept open by pump¬
ing

Springs.

When a stream cuts its channel down
below the ground water level it taps this
underground reservoir just as a well does,
and water oozes out of the soil at favor¬
able places in the form of springe. In
some places streams will have only cut
down to the level to which the water
table rises in winter. In these cases
the springs will only function in winter,
and in summer, as the water table drops
lower, they will cease to flow. In other
cases the streams have cut down below
the lowest summer level. In eastern
Tasmania the variation between summer
and winter level is considerable. It is
these springs which give the streams their
regular flow. If the water table drops
below the stream’s bed in summer the
main source of supply is cut off. and tke
stream ceases to flow until further rain¬
fall replenishes the supply. Only those
streams which arc sufficiently large to
have cut below the summer level are
perennial. The streams with steep-sid¬
ed, deep gorges have more chance of
tapping this supply than those with
wide, open valleys, as in the latter case
the water table tends to conform with
the contour, and is not cut by the
stream.

Besides this water underground tra¬
vels along the dip of the strata. In
doing this it may find a natural outlet
as on the side of a mountain or mav
accumulate against an impervious rock
mass until the level rises to the sur
face at a particular spot which is 1< w. r
than the main source of supply.

Artesian Basins.

In continental areas a pervious rock
mass may cover many thousands of
square miles. If the passage of water

downwards is prevented by an impervi¬
ous layer the water may accumulat in
a great underground reservoir, and l e
tapped by wells or bores. If a cor -
siderable area is higher than the pla e
where a bore is sunk the pressure i*l
water there will force water out of
the bore with often great force as s oi
ten the case on the mainland, where the
rainfall caught on the plateaux of the
Dividing Range soaks underground to the
plains to water the dry paddocks when
released by bore holes.

Ill other areas the water is present,
but there is no pressure to cause it to
rise. If a well is put down water can
be pumped out. Such a place is teim
ed a sub-artesian basin. Many of these
exist throughout the midlands and sout i-
e a stem Tasmania. Here the requisite
conditions are a bed of Ross sandstones
overlying a bed of hard permo-carbon
iferous silicious mudstone, as we shall
see later a very usual occurrence. Th"
water acumulatos in the sandstone and
cannot escape through the underlying
mudstone. A borehole or well sunk into
the sandstone will yield water, only
pumping for ten to fifty feet being re¬
quired to ensure a steady supply.

Caves.

Water travelling underground soon
wears for itself well defined clmnn !«
which in time develop into caves. Tlii-
is especially the case in limestone cou.i
try where the mechanical action of the
flowing water is greatly reinforced by
the chemical action, mainly the effect
of carbon compounds picked up frrm de¬
caying vegetation on the surface dissolv
ing out calcium from the limestone.
Where the limestone beds are very m a
sive and of great antiquity wonderful
caverns may be hollowed out. In the
rase of limestone caveB these are l eai -
tified by deposits of calcite until they
present sites of most surpassing won
der. Drips of water from the roof, car
rying a large load of lime, deposit soim
of this on reaching air. More is deposite
when they drop to the floor and dry
Thus are formed stalactites (growin/
down from the roof) and stalagmite*
(growing up from the floor). As tin
volume of water, the lime content and
the form of deposition vary from drip
to drip a wondrous variety of forms
grow In the cave. Smooth, untapenng
glass-like tubes, candles, pillars, no
common forms. Often water flowing
over the surface make knobs of fanta-t e
shapes, often tiny drips drying at dif¬
ferent points on the tip of a tube give
it a twisting form; sometimes water
exudes from a crack and forms a shawl

(2)

THE TASMANIAN NATURALIST

or screen of transparent, white lima
rock. Again, differences in content
give a “bacon’Mike appearance. In
fact, each stalictite must be described
to include all forms. These limestone
caves are one of the greatest wonders
of nature. They are common in Tas
mania wherever we have beds of very
ancient limestone. The best known are
at Mole Creek, Chudleigh, tTlverstone,
.Tunee, Florentine Valley, Hastings and
Ida Bay.

Water at Beaconsfield.

To give but one example of the travels
of underground water, the Tasmania
mine at Beaconefield, our largest gold
mine, had to close down on account of
the volume of water that it made. A
million gallons a day had to be pump¬
ed out. Chemicals placed in water in
the Chudleigh caves 60 miles away were
traced to the mine. And there is the
old legend—unhappily untrue, but wide •
ly believed even yet—of the dog that
wandered into the Chudleigh Caves and
appeared in the mine at Beaconsfield.

Section 15.

THE DEPOSITION OF
SEDIMENTS.

We have already seen that various
agencies are at work continuously reduc¬
ing the surface of the land. As little
material leaves the globe, the vast quan¬
tities of soil and rock waste removed
from their original site are merely re¬
distributed. Ultimately, rivers are the
great transporters of the particles torn
from the parent rocks, and the river
mouths and adjacent coasts are the great
repositories of the material carried from
the land surface- The size of these par¬
ticles of the land surface so carried to
sea varies with the power of the river
to transport weights, but in all cases
the finest grains greatly preponderate.
When given a chance, this material settles
and hence is called a sediment. The usual
land detritus settling close to the shore
is called a littoral deposit.

Other types of deposit are met with.
Those which are moved from their original
site by wind and are piled up elsewhere
on the landscape are termed terrestrial
deposits, and the same name is applied
to dust deposited by a volcanic eruption.
Rivers may drop sediments in lakes, when
they are called lacustrine deposits, or
along their own banks, when they are
called fluvatitile deposits. Then, besides
rivers, glaciers also carry a considerable
amount of rock waste. This is dropped

where the ice melts and is termed a
glacial deposit. Finally enormous depths
of “ooze” accumulate on the floors of
the great ocean deeps from the remains
of animal organisms, and from chemical
precipitation. These are called deep 6ea
deposits. Each type has its special pe¬
culiarities resulting from the manner of
its deposition. It is necessary to knew
these, because they are preserved through¬
out the subsequent history of the sedi¬
ment as a rock, and after many changes
always give an unmistakable indication
of the state of the locality where they
were first deposited. This forms, as we
will see later, the basis of geological

history.

Littoral Deposits.

By far the greater quantity of material
worn from the land finds its way by
storm water channels to streams, and
thence by rivers to the sea. As ex¬
plained before, the river’s ability to carry
a sediment load depends on the force of
thp current A river’s current cannot
make its power felt against the sea, which
soon brings it to a standstill. Where ibis
happens, most of the sediment load is
deposited. When the current begins to
icel the drag of the tidal waters of the
river s mouth, the heaviest nortions of
the river s load, the big boulders which
jt can just push along its bed* no longer
have sufficient pressure behind them to
be moved, and stay in the place where
they were left when this pressure was
reduced below the minimum required to
move them. Gradually as the force of
the current becomes less and less, finer
and finer particles are left behind. This
is referred to as the sorting of the sedi¬
ment load—the heaviest materials being
dropped first, and the sediments shading
thence to finer and finer grains as the
shore is left behind, until within 100
miles of the shore little or no sediment
trom the land remains in the waters of
the ocean.

To these sediments are added those
worn by waves and tides from the coast
and particles blown from the land into
the sea all of which commingle, but the
ii\er and stream sediments always greatly
preponderate. The ocean currents func-
tion much as rivers and move sediments
along the coast*, distributing them over
the continental shelf, but sooner or later
these sediments come to rest in the deeper
and quieter waters, and accumulate un-
tu some change of conditions brings
about a cessation of the supply of sedi¬
ments^ and alteration of currents a differ¬
ence in relative positions of land and
sea or a change in depth.

At its bottom such a deposit of sedi¬
ments must rest on the older sea floor.

(3)

THE TASMANIAN NATURALIST

If this is close inshore, it will be broken
by the waves and boulders of this rock,
and will become included in the lower
level of the newer sediments. Besides
this, the sediments near the shore will
be in general course, and gradually fining
out with distance until at no great dis¬
tance only the finest mud will be found.

The remains of animals, such as shell¬
fish, will drop to the bottom and be¬
come incorporated in the sediments. Some¬
times these remains form the bulk 91
such sediments; for example, at Maria
Island there is a bed of limestone a thous¬
and feet thick composed entirely of re¬
mains of ancient shells. Coral also ac¬
cumulates to a great depth. Also pldnt
remains may form a large proportion of
the mass of sediment deposits in certun
places, as enclosed lagoons on low coasts,
mangrove swamps and seaweed beds.

From all the various types of rocks
into which thes e different natures of sedi¬
ments are ultimately turned, and which
will be discussed later, an idea can be
formed how far from the coast the spot
where the rocks now are, was when me
original sediments were deposited. These
simple rules of deposition are unalterable
physical laws, and their evidence is in¬
controvertible.

Terrestrial Deposits.

Over great continent masses there is
a constant resorting of rock particles.
Higher elevations are denuded by frost,
wind and rain, and the waste is dis¬
tributed over the lower basins. On the
mainland, most of the great Murray-Durl-
ing basin is built up to a depth of up
to a thousand feet of sediments actuary
deposited where they are now seen, on
dry land- In desert regions, this is even
more pronounced, and everybody knows
of the shifting sand hills of central Aus¬
tralia. Wind is a most active agent in
the deposit of these sediments. They
present man} r differences from marine de¬
posits, which will be discussed in our
chapter on Petrology. In Tasmania this
form of sediment is represented chiefly
by sand dunes, composed of fine par¬
ticles of rock worn by the wives from
the coast or of portion of the sedimentary
load of a littoral current, left at high
water for breezes arid winds to blow
inland during low water. These aunes
spread far inland, and cover a great area
to a good depth in some places, especially
on the West Coast-

Lacustrine Deposits.

Rivers drop their sedimentary ioaa
when their flow is checked by a lake
in much the same way in which they

do when they enter the sea. Deposits
in a lake closely resemble those in the
sea, and the two forms are difficult
to distinguish if the Jake is large. Ab.
sence of marine organisms is a test.
Also, especially if the lake is small,
a river may in time of flood extend its
current much beyond ordinary limits, 1
thus giving a greater irregularity in
matter of size to these deposits, and
the sorting and distributing effects of
tide and currents Is absent.

Fluviatile Deposits.

Rivers, In many portions of their
courses, have quiet reaches. Here they
often deposit a bed of sediment- In
flood time, when the current, which is
swift and powerful in its course, over¬
flows surrounding plains, it there tends
to bear resemblance to a lake, and any
sediments that And their way into that
part are usually left there. Thus large
beds of sediment are often built up In
the flat portion of the valleys over¬
flowed by the river during flood time.
These are termed flood plains. They
and the smaller fluviatile deposits form¬
ed in bends and on low banks of rivers
are distinguishable by their small ana.
quick variations in nature, and because
they are usually less sorted than sedi¬
ments dropped in lakes and in the sea.

Very often they give a level effect to
the river valley. It is common for
rivers to be cutting out their valley
In their upper reaches and depositing »
flood plain over it in the lower reaches

Glacial Deposits.

Water can npver stop suddenly, and
it always has a certain amount of
sorting action. A glacier or ice sheet
melts at a given point. Here every,
thing that Is being carried drops. There
can therefore be no sorting. Every
atone, from boulders the size of houses
to clay grains, are to be seen piled on
each other in one huge rubble heap. If
the glacier is melting in one place for
a long while a mound—often resqinbl-
Ing a high railway embankment—will
be built up. If the ice is gradually ex¬
tending its field or retreating—the usual ,J
case—this material will be strewn with¬
out arrangement, and generally in ir.
regular heaps and lines over the glacial
The striking difference between a sort
ed deposit and an unsorted one Is the
first indication of past glacial action.
These deposits are usually termed
"moraines." although strictly speaking
a moraine is the debris actually being
carried by the ice. Various distinc-

( 4 )

THE TASMANIAN NATURALIST

tions, such as terminal moraines (the
debris dropped oft the end of a melt¬
ing glacier), lateral and medial mo¬
raines (that carried on the sides and in
the middle of the glacier), kames and
esker ridges (deposits in engiacial
streams) are indistinguishable in Tas¬
mania, and probably everywhere where
these deposits have been exposed to rain
and weather for a considerable time.
Often glaciers drop single boulders—
known as “erratics,” or perched blocks:
this cannot be done by water.

Deep-sea Deposits.

Sediments from the land do not reach
the great ocean depths. Still, these
are covered with many thousand of feet
of deposits, which present special cha¬
racteristics. In the first place their
structure is very massive. The layers
are of great depth, as conditions do not
change quickly. There are none of
those quick alterations of strata com¬
mon in inshore deposits. Currents,
wind, floods, and changes of position of
neighboring land have little effect.

The second great difference is in the
materials. Sand, lime, terrestrial and
coastline, plant and animal, remains
are not carried out into the ocean.
Their place is taken by “ooze," composed
of fine volcanic and w»ind-blown dust »ti
small quantities, with the bulk of the
deposit consisting of remains of micro,
scopic sea animals, and chemically de.
posited minerals dropped by precipita¬
tion

Tasmanian Examples.

Examples of these deposits are too
numerous to mention in detail. Most ot
our rocks are formed from one or the
other. The common mudstones and
limestones were once littoral deposits
Terrestrial deposits are represented by
the sand dunes common round our coast,
and probably by many of our sand¬
stones. Coal measures give us exam¬
ples of lacustrine deposits. Many of the
clay beds come also under this heading,
especially those of Launceston, Corne¬
lian Bay, and Kingston. Fluvlatile
deposits abound along every valley. A
walk along the Derwent or Esk or
Mersey silvers, to mention only three,
show these deposits at every step. The
west coast and the higher mountain
ranges are covered In many places with
glacial deposits, and the limestones ot’
Railton, Mole Creek, Ulverstone, Ida
Bay, and the Cordon River are prob.
ably deep-sea deposits. These will ail
be referred to in more detail later.

Section 16.

THE LIFE HISTORY OF A
LANDSCAPE.

A Young Drainage System.

When a given region has been recent¬
ly uplifted, the courses of streams and
the topography of their valleys and the
divides between them present features
showing that the effects of water ero¬
sion have only been left for a very short
period. The time factor is unimport¬
ant. A stream working in soil or
very soft rock will complete the maxi¬
mum erosion in its power very much
more quickly than one running over
country composed of a very hard rock.
Similarly one with a large and continu¬
ous supply of water, or with more
power given by greater height, will re¬
duce the features ordinarily characteris¬
tic of a short period of operation much
quicker than a small, intermittent
stream or one unfavorably situated in
regard to slope, or possessing barriers
to its erosion. A young drainage sys¬
tem, therefore, implies not so much a
system that has commenced eroding the
given landscape recently, as a system
possessing the characteristics of one that
has not had time to effect much erosion,
even though it has been at work far
longer than a more mature system,
which has in these ways had an easier
task, and has completed it in a shorter
time.

This early stage in river erosion is
marked by many small and often paral¬
lel streams—the water taking the
easiest line of slope. The streams have
considerable power owing to the slope
and as they cut the bottom of their
channels quickest, they run in deep,
steep-eided gullies. Between these are
wide and often level divides. The whole
power of the stream being conc?ntrated
on its bed. there is little deposition,
except, perhaps, where it reaches flat
country with its mouth. There are
few harriers to make it bend, and these
are soon cut away; therefore it is gen¬
erally faifrly straight coursed. If the
uplift is quick, the river’s bed will be
steep, and rapids will result; in ex¬
treme cases inland cliffs will he de¬
veloped and result in al waterfall. A
basin will fill with water as a lake or
swamp. Given time, a stream will cut
away a rapid or waterfall, as here it
has greater power and will fill a lake
with sediment. Hence rapids, water¬
falls, and lakes are a sign of youth.
Tributaries will be mere drainage from

(5)

THE TASMANIAN NATURALIST

the valley sides, running straight to
the river at the bottom of the valley,
and so will tend to enter the main river
more or less at right angles. These
rivers, being in general above the
ground level and fed mainly by rain-
tall, and having small catchment areas,
will tend to vary greatly in their vol¬
ume. Any of these characters show
that a given drainage system has been
eroding the landscape for a relatively
short space of time.

The Adolescent Stage.

As the orderly process of river erosion
proceeds, those portions of the bed with
the greatest slope will be worn away
first. Thus waterfalls and .hen rapids
soon disappear, and lakes are removed.
Then as rivers erode their valleys chief¬
ly at the head—that is, where the slope
is greatest — the high land separating the
heads of systems will be reduced, and
the tributaries, each doing similar work,
will reduce the divides, until ultimately
the former level plateau will be reduced
to a line divide, and valleys of various
river systems will occupy the whole land¬
scape.

Detailed characters for this stage can¬
not be given. The general straight line
profiles have become rounded. The rivers
flow in valleys and not canyons. The
divides' resemble ridges rather thin
plateaus, and in general the topography
can be spoken of rather as a series of
river valleys separated by high divides
than as a plateau cut by gorges. How¬
ever, the boundary lines between youth
and adolescence an dadoleseence and ma¬
turity are vague The stage termed ado¬
lescence can best be described as a
stage in which the characters of youth
have been removed by the Iong-continu-
ed process of erosion, but those of ma¬
turity have not yet had time to de¬
velop.

The drainage of a region os said to bo
in the nature stage when the streams
have just completed all the erosion they
are capable of in the existing cireum
stances. As a river erodes the landscape
by cutting down its bed with sediment
carried along ami by thus giving its tri¬
butaries a levwl to which to erode their
beds, it follows that a point must be
reached eventually at which the river
has no longer sufficient slope to give it
power to carry a sediment load. A river
system obviously cannot plane the land¬
scape level. Some slope must remain, and
the altitude at the head of a long sys¬
tem will be considerable. Water requires
a drop of about 4 fee<t a mile as the
minimum slope to enable it to flow. A

river would probably cease to erode when
the level had been reduced below 10 feet
per mile, and in most cases would not
have power to do much erosion long
before this limit i« reached. Similarly
the divides between systems could not
be completely removed.

The general aspect of a landscape with
mature drainage is that of wide rolling
plains unbroken by sharp features or
steep slope®. The original plateau is all
gone, and only a succession of river
basins remain. This type of landscape is
termed a peneplain—almost a plain—the
nearest approach to level to which river
erosion can reduce it.

Drainage Systems in Old Age.

If no alteration of strand level occurs
and the mature system persists for a
long period, the drainage passes into the
stage of old age. Although in normal
times the rivers cannot cut lower, periods
of flood occur occasionally hiring which
the bed iis cut lower than the stream
can in normal times transport its sedi¬
ment load. This is then deposited over
the broad valley when the viver's power
is normal. Even a further stage is reached
when the river cannot carry any sedi¬
ment load over a great portion of its
course as tlii* slope is too gentle to give
it the power. It' then builds a wide
flood plain over its valley. The force of
the river having gone, the water mean¬
ders, often in a series of bows, through
this plain. Floods cause frequent changes
of course. The tendency to bend is
aided by the slightly increased power
given to tho outward side portion of the
current on the turn. Often the stream
cuts across the base of one of its bends
or cuts into the points where the bends
commence until they meet nnd leave a
straight path for the stream. The old
course in the bend then becomes a la
goon or billabong. A glance at a map
or aerial photo of the Murray or Dar¬
ling will show these feature® in every
stage. A caution must, be given here. In
a newly uplifted area the drainage is still
indeterminate. Rivera flow everywhere.
None has yet developed predominance.
The general level its not broken and lake®
abound. In some respects this resembles
a system of old age, but the lakes,
swamps, and haphazard arrangements of
the river courses show that it is not so.
This type is known a'- - plateau drainage.

Rejuvenated Drainage Systems.

Beyond old age a river cannot go. In
the great stable centres of the continents
the> systems have long ago reached this

(6)

THE TASMANIAN NATURALIST

stage, and now merely pile* more and more
sediment over their plains and meander
through these deposits. The best known
examplo to us is the Murray-Darling sys¬
tem, which around Milduri, ;or example,
Hows over its own flood plain six hun¬
dred feet thick. This has been piled up
to such an extent that, although distri¬
buted until it is unuotkeable to the
naked eye, the streams of the Wimraeru
and Malice cannot flow uphill to meet
the Murray and vanish in -alt swamps
behind the flood plain. Many of our
features have not yet been established,
and there is at present a great contro¬
versy as to whether the landscape of our
central plateau and east and southern
districts is due to diabasic uplift fol¬
lowed by a long period of erosion chiefly
influenced by differential resistance of
various beds, or whether, as the writer is
inclined to think, it is due rath err to
block faulting in the recent past. Until
this is established we cannot be quite
certain as to the development of our
landscape.

River Piracy.

In this process of development from
vouth to maturity one of the striking fea¬
tures is the way in which certain main
rivers take the place of many small
streams, and these large rivers are fed by
a network of tributaries, resembling in
plan the branches of a tree, which system
takes the place of a large number of
small, independent streams flowing rough¬
ly parallel to each other—one of the char¬
acteristics of a youthful drainage system.

Of two or more parallel rivers, it usually
occurs that one or more are more favorably
situated than the others, by reason of
greater initial catchment area, greater slope
or softer rock beds, all of which factors tend
to allow them to outpace neighboring
♦dreams in the work of erosion. These
rivers erode their sides of the divide, thus
widening their valleys at the expense of
those of their neighbors. At the same
time they also push their heads further
into the plateau mass. The result is
greater catchment area, and hence greater
water supply for erosion. This, added
to any other advantages, often enables
these streams to cut deeper channels than
their neighbors. This greater depth gives
greater power to tributaries. If one of
these tributaries by headward erosion cuts
right through the divide into the valley
of the next stream, it will eventually be
flowing at a lower level than that stream
and will tap all the water flowing in at that
point, diverting the whole system above
to its own course. Tn this way, one large
stream will capture the headwaters of

many smaller ones, and eventually en¬
large its catchment area to include a
great proportion ot the hinterland, and
leave the many original streams repre¬
sented only by short trickles on the
coastal slope. A liver which has had its
headwaters so captured is said to be “be¬
headed.” This process naturally increases
with every additional capture.

The great inland drainage systems of
old established continental areas are large¬
ly due to this cause. The drainage has
been captured by one or more master
systems, which have extended tributaries
over much of the interior of the area,
draining all except the actual slope to
the sea, and continually pushing tne di¬
vide between their system and that slope
nearer to the coast. A marked right-
angled, or hairpin, bend in the general
direction of a big river, is very often a
sign of such a capture, the original course
of the upper portion having been diverted
to the general course of the lower.

These processes take place during the
change from youth to maturity. They
may be seen in every stage in most sys¬
tems, but not until they are more or less
complete does the adolescent stage pass
into the stage of maturity.

Firstly, as to rise and fall of the land,
we see, a*> explained before, that at no
great distance in the past the effects of
river action were felt at a lower level
than now, as evidenced by the many
waterworn valleys now Hooded by the
sea in the form of the estuaries at the
mouth of mot of our rivers. This rise
of the strand level has been followed by
a slight sinking. Today we see most of
our rivers ,notably on the Derwent be¬
tween Macquarie Plains and Bridgewater,
and on the Mersey above Latrobe, beds
of river conglomerates^ portions of old
flood plains, now high above any pos¬
sible flood level, indicating that in r<>
sponse to rise of the level of the land or
sinking of the sea level, the riven* are cut¬
ting into their old flood plain.

One possible reason for this is com¬
mon, and must be watched <*or as it is not
connected with rise or fall of the land.
If a river flows over a bed of hard
rock near its mouth, and this bed is not
very thick and rests on beds of softer
rock, the river will not be able to cut
quickly through the hard rock and the
level of this will represent the base level
for the valley above it. The river may
succeed in reducing the topogrnnhv of its
valley above the bar of hard rock to
maturity. Then it may cut through the
bar and deepen its course quickly in the

(7)

THE TASMANIAN NATURALIST

soft beds below. The result will be a
rejuvenation of its course in the higher
levels.

Although this occurs in stable conti¬
nental regions, these are lew, and a sys¬
tem in most parts of the world seldom
reaches even maturity. A new strand
level is prouuced by earth movements
alter the cycle has proceeded a certain
distance. 11 the landscape has reached
a stage when the drainage is mature
and is then elevated tht«e streams will
be given new power by the increased
siope to the sea. The same happens ii
me level oi the sea drops. I hey are said
to be rejuvenated. At drat they cut
deep young channels into their oio valley,
and then the cycle of erosion commences
again, its course depending largely on the
amount and rate of uplnt. Tins young
valley cut into the mature me is termed
**a valley within a valley landscape/' If
the old river has been meandering, it
probably will be unable to move out of
its old course and will cut a gorge fol¬
lowing its former bed. This is termed a
river with “entrenched meanders/* When
the re-elevated peneplain a* again reduced
to a stage approaching maturity, hills
will stand out the remnants oi the old
peneplain, and these will have tops rela¬
tively level and at approximately the
same elevation, all that is left of the old
sand surface. These are termed “pene-
plainal residuals/'

Having discussed the various processes
bv which a given landscape is formed and
moulded, wo must turn to an examination
of the characters which tell us how long
these processes have been at work, and
the relative order of their occurrence. A
landscape may be newly uplifted, or may
have not felt the influence of earth move¬
ments for an infinite length of time. The
river system may have been at work
eroding the surface during all this time,
or it may have been interrupted. It is
the various features of the landscape
which give us an indication of these hap¬
penings that we must now study. This
is sometimes called the cycle of erosion,
but this title is confuting, as only one
particular phase can be seen in one place
and one given locality, seldom even in
the whole course of ecological time com¬
pletes the cycle, the movement being often
as much backward as forward. Also
different phases can only be seen over
large areas, although small variations in
the phase of erosion may occur from
place to place.

Effects of Rise or Fall of the Land.

A given tract of land is more often
slowly rising or falling in response to

earth movements explained previously
than it is stationary. As has been ex¬
plained, streams, in order to erode thoir
valleys, require velocity, and this is
imparted by slope. Also for an increase
of one in velocity their eroding powei
is increased 27 times. As a stream can
only erode in its bed, and an uplift gives
it such a great increase in power, it
immediately starts to entrench its bed,
to cut a narrow, steep-sided gorge in
the bottom of its valley. Tributaries con¬
form and in turn cut deep valleys, where
they join the main stream.

On the other hand, if the laud is sink¬
ing, the transporting oower oi the rivers
is being reduced. They must deposit sedi¬
ment loads which they were once able
to carry out to sea. Thus alluvial plaius
are the rule, and valleys tend to become
shallow and flat-bottomed as they ai
tilled with sediment deposits. Thus we
get the first indicating mark of the im¬
mediate past history of our landscape.

If the rivers have* been eroding their
valleys evenly for a long time, the land
is probably stationary. If, within their
old valleys, they have recently com¬
menced to cut deep, narrow channels, the
land is rising. And if they are now
depositing sediments in valleys they pre¬
viously cut out of the surrounding land¬
scape, the land is probably sinking. This
rising and sinking of the land is the
first matte r to be determined in decipher¬
ing the history of a landscape. It is
so usual that it upsets the regular work
of erosion many times in one cycle, ajid
is often the true explanation of many
features elaborately explained away by
involved theories of river erosion. It
must also be remembered that the sea is
also ri ing and falling in response to melt¬
ing or otherwise of polar ice sheets, for¬
mation of ocean deeps, etc., and it is
of ton impossible to be certain whether
it is the sea or the land that is moving.
To avoid this difficulty, we usually speak
not of the rise or fall of land or sea,
but of strand level, that is, the place
where land and sea meet, as the phe¬
nomena on land are the same whichever
cause operates.

Effect of Alteration of Strand Level
on Coast Line.

It is at the sea coast that the records
of rise and fall of strand levels are es¬
pecially recognisable, and as the deter¬
mination of these movements is so im¬
portant, it is necessary to look at the
coast line before endeavoring to inter¬
pret the history of our landscape.

( 8 )

THE TASMANIAN NATURALIST

In the first place, a straight coast
line, or a coast line formed of series of
straight-fronted segments jointed to each
other, is generally a mark of uplift. The
lengthy work of streams and the ac¬
tion of the waves and the weather tend
to produce inlets where streams wear
out valleys, leaving headlands and ter¬
minating the inter-stream divides, and
these and the other agencies tend to
cut out the softer portion of the coast,
leaving the more durable portions as
capes. Again, cliffs show a recent up¬
lift, as these cannot long endure the ef¬
fects of the weather and streamlets,
especially when the great increase in
eroding power given by such a slope is
borne in mind. It must, however, be
borne in mind that a sudden downward
faulting of the segment under the sea
bordering on the present land will give
the same results, as the unfaulted land
then presents a straight face to the
flooded portion, which has now subsid¬
ed.

Conversely a ragged coast line, with
intricately etched front, indicates a sink¬
ing land, as the sea flooding over the
subsiding landscape covers the country
following a given contour round the
many gullies and valleys worn by small
and large watercourses. The waves in
general wear the shore in a fairly regu¬
lar line. Very many small inlets and
capes indicate that some agency other
than waves has produced the form of
coast line. This generally can only
have been done by submergence of a
topography, already moulded by water
action.

Therefore in examining a coast line
for rise or fall of land, the first ques¬
tions an observer must ask himself are
whether the features he now sees could
have long resisted the attack of weather,
waves, and streams in their present
form, and whether waves and existing
streams and rain-water channels cculd
have produced the features he now sees
where they now exist.

More detailed evidence may be avail¬
able when these questions are deter¬
mined. For example, the existence of
soft, recently-laid marine sediments on
what is now dry land—a feature term¬
ed a coastal plain—is sure indication of
a recent uplift. So also are raised
beaches—shell mounds and other typi¬
cal bench formations high above the pre¬
sent level of the waves, wave terraces
cut in places well above present high-
water mark, cliffs obviously wave-cut,
now seen well inland, and wave-cut
caves far beyond the present reach of
the sea.

On the other hand, drowned valleys
estuaries that must have been cut by
rivers, but now occupied by the sea in
sucli a way as to prevent erosion by the
•ivers that enter them—arc sure indica¬
tion* of a sinking landscape. So also
are islands in groups off the coast, which
are obviously the tops of submerged hills,
and could not have been formed by
more resistant cores uf bard rock left
standing beyond the general front of
the eroded coast line.

It must be borne in mind that these
phenomena do not necessarily show pre-
Kent elevation or depression They only
show that these movements occurr d at
a time so recently past that the traces
have not yet been obliterated. The
movements may have stopped for some
time, and a contrary movement may now
be in progress. The general condition
o; coast lines is that of continual oscil¬
lation with, however, either an upward
m downward movement predominating.

Recent Rise and Fall of Tasmanian
Coasts.

Our coast line in general shows all
ound the island a general sinking,
which movement, after being very pro¬
nounced unt’l recent geological times,
has now changed to one of general ris¬
ing. Our great estuaries, the Derwent,
Huon, Taniar, Mersey, and others all
show signs of having been worn by
rivers. Since this they have become
Hooded by a general rise of strand level.
Our numerous harbors have been form-
id in tins way. But it must be remem¬
bered that in recent geological time the
level of the ocean has risen about 150ft.
through the liberation of water former¬
ly locked up in the great ice sheets of
Pleistocene times.

The straight lines of the east, south¬
west, and southern coasts, and the
numerous linos of high cliffs there, m-
licate a recent dropping away of the
sea level to a slight degree are shown
by the numerous raised beaches com¬
mon round our coast, and standing up
to 25ft. above sea level in the south¬
east, and several hundred feet in the
north-west. A very marked shore plat¬
form runs round the base of the cliffs
of south-eastern Tasmania, and is con¬
tinued up the Derwent estuary at Belle-
rive, Bedlam Walls, etc. On the north¬
west coast a small coastal plain is very
marked. The railway from Don to
WynyanJ runs along this, and the old
line of cliffs is clearly seen in the line
of steep hills rising immediately behind,
especially at Wyvenhoe and Burnie, Al¬
together the tendency at present appears

(9)

THE TASMANIAN NATURALIST

to be a general rising level of the land,
this being more marked along the fiass
•Strait coast, especially in the north-west
and least marked, but still decided, in
the south coast.

The Cycle of Glacian Erosion.

Glaciated landscapes snow a similar de¬
velopment from youth, through adoles¬
cence to maturity and old age. The
characteristics naturally are different as a
glaciated landscape differs so materially
in general aspect from a waterworn one.
As so much of Tasmania shows the im¬
print o. recent ice-erosion passing men¬
tion must be made to these types of land¬
scape. These characters depend chiefly
on the length of time during which they
have been exposed to ice action. Slope
lias relatively little bearing, but its place
it taken by quantity of ice which in turn
depends on precipitation.

When a glacial period commences na
lurally the higher elevations arc tile first
affected. As far as Tasmania is concerned
these are the only regions to be seiiously
considered. The manner of the develop¬
ment of cirques and other glacial features
has already been considered. As it is by
cirques that ice chiefly models the land¬
scape these are the features to be con¬
sidered in studying the cycle ot glacial
erosion, lee caps will be liseussed sepa¬
rately later.

The Youthful Channeled Upland.

The first effects of glaciation are the
appearance of the summer snow bank,
‘‘dug in’ 7 by its own erosive work in a
hollow of its own making. This hollow
ultimately develops into the cirque The
earliest stage in glacial erosion is seen
when the upland is grooved by numbers
of cirques at the head of U-shaped glacial
valleys. The form of the original upland
still persists and the cirques are obviously
cut out of it. Broad plateaux remain
between them and at the heal of, a group
of radiating glacial valleys much of the
original plateau can still be seen. The
cirque is the distinguishing feature of
this stage.

fhe Fretted Upland or Adolescence Stage.

As erosion proceeds, the sides and head
of the cirques are enlarged by the in¬
tense frost action along the in ration zone
and by the plucking action of the glacier
ns previously explained. Cirques, which
first were regular troughs, become “nail-
headed.” and then multiple, this latter
stnrr«» being reached when the glacier
renllv orows from a number of cirques
cnnar'ifnd hv rock buttresses. The cirques
and U valleys enlarge sideways until

eventually they meet. They first join not
right at their heads, but iome distance
down at the broadest portion of the
cirques. By this time the original pla-

leau is reduced to a series of ridge*, very
little of the original surface beiug left.
These ridges present knife edges, often
with a very sharp contour, markedly dif¬
ferent from the rolliug contours of water
divides. In time the ice in the cirques
eats right into the ridges. Not along their
whole length as a rule, but in spots at
often regular intervals. Here the ice
removes the original surface and leaves
the rock between standing as a scries of
pinnacles. These ridges have been

termed “comb ridges,” and ire the typi¬
cal features of this stage. The process
has been compared by Professor W. II.
Hobbs, the leading worker in this branch
of physiography, to the process of cut-
iuir biscuits from a sheet of dough with
a biscuit cutting mould. When the maxi¬
mum number of biscuits have been cut
from the dough, thin strips are left be¬
tween the portions so cut out. A glaciated
landscape in this stage of erosion resembles
flic sheet of dough when the maximum
number of biscuits have been rut out.

The Glacial Horn of Maturity.

As the process continues the ridges
nr#» gradually reduced. At first the&e
ore somewhat at the same height a*
that of the original plateau. These
connecting ridges in a glaciated topo-
a* aphy are termed cols- Early matu¬
rity represented by high cols. Gradu¬
ally these are lowered, and in a later
stage become low cols. In the course
of tim P they disappear, or almost so.
Theu all that is left is the original col
of the plateau, or that portion which
stood at the head of a group of glaci¬
ers. This now stands out as an iso¬
lated mountain peak, termed a glacial
horn. The Matterhorn is the type of
this feature par excellence.

The Monumental Upland.

Beyond this stage glacial erosion sel¬
dom proceeds, but Professor ITobbfi •
h is discerned a further stage in Glacier
National Park, U.S.A., and another
class has to be mad*-. When the
Glacial Horn is subjected to still fur¬
ther prolonged erosion it gradually dis¬
appears. Then the whole interior of
thp original plateau has been reduced
to a level. But the point at which the
erosion by this agency is least felt is
at the edges of the plateau, at the ends
of the cirques. Thus after the interior
‘herns have disappeared Took masse*
still stand out at what was originally

( 10 )

THE TASMANIAN NATURALIST

the lower ends of the cirques. These
arc termed monuments, and when they
alone are left the landscape is said to
have reached the old age of glacial ero¬
sion . These monuments naturally
stand in pairs, one on either side of
the original cirque. Continued ice ero¬
sion then tikes the form of ice cap
erosion, and not glacial erosion, and
an ice cap, beyond a general levelling
effect, does little work in reducing the
level of the landscape.

It must filially be noted that there
is not in glaciated landscapes the or¬
derly progress from youth to old ag^
seen in water-worn landscapes. One
stage dope not follow after the previ¬

ous one is completed, but each of the
more manure exists with the mere
juvenile stage, but in an embryonic
form. Thus in the early fretted up¬
land flip portion which will ultimately
form the glacial horn is to be seen
standing well above the general level,
and the future monuments are also
beginning to appear. As the erosion
proceeds from stage to stage, the later
forms, always noticeable, become more
pronounced.

Of course, a glaciated landscape can¬
not be studied until the ice has disap¬
peared, or almost so.

A. N. Lewis.

Some Notes on the “ Wattle ” or “Acacia

(Continued.)

1 have here some statistics for the year
ending June 30, 1923. Wattle bark ex¬
ported from Tasmania was 53,222cwt.,
valued at £25,474, of which £16,059 was
from Hobart the remainder from Laun¬
ceston. Quite lately a shipment was
sent direct from Bridport, 12 miles from
Scottsdale, to the mainland, the first to
be shipped direct. There is about £000
worth of wattle bark used in this State
for tanning purposes every year, which, in
addition to exports, it will be seen that
it is very valuable.

Mr. Mitchell, on East Coast, had a plan¬
tation of black wattle harvested once in
seven years gave the largest percentage
t i tanning under cultivation.

The black wattle contains 38 degrees tan¬
ning, the silver wattle 24 degrees, approx¬
imately.

Imports of Wattle Bark Into Australia,
1922-23.

Importing States. Quantity. Value.

cwt. £

New South Wales . . . 35,745 .. 14,032

Victoria. 54,463 .. 21,070

Western Australia . . 3,458 . 1,593

Total. 93,666 .. 37,301

Note.—With the exception of 6 cwt of
Australian bark re-imported, all of the
above imports were received from South
African Union.

Imports of Wattle Bark Extract,

1922-23.

Country of Origin. Value.

£

United Kingdom. 64

South African Union.2,878

United States of America . 25

Importing States.

New South Wales.1,626

Victoria. 608

Western Australia. 733

Total .2,967

Exports of Tanning Bark (So Described)
from Australia, Produce of Australia.
1922-23.

Country to Which

Exported.

Quantity.

cwt.

Value.

£

United Kingdom

... 12 .

3

Mauritius.

. 309

194

New Zealand . .

. . 11,034 .

7,604

China.

. 2,478 .

. 1,385

Japan .

.2,003

826

Netherlands, East

Indies . 9

9

Total.

.. . 15,845

10,021

Commonwealth Bureau of Census and
Statistics, Melbourne, May 19, 1924.

Note.—In addition to above exports,
l,084cwt., valued at £695. of tanning
bark produced in other countries were
exported from Australia during 1922-23.

I would point out at this stage that

(ID

THE TASMANIAN NATURALIST

South Africa Got the Seed

of this wattle from Australia, and now
is exporting wattle bark in the quantities
just named to Australia. Australians
should try and grow enough wattle to
supply all their needs, and also to ex¬
port more. Returns from the South
African Union show that in one year over
£975,000 of black wattle bark had berm
grown, shipped and sold.

Blackwood timber exported from Tas¬
mania for the year ending June 30, 1923
(dressed and undress and log) totalled
3,010,000 super, feet, valued at £59,500.
These figures, taken with what was used
in Tasmania, show that it is a very valu¬
able asset to our country, and should be
conserved in every way; and by growing
young wattle for stripping and getting
blackwood seed, and raising seedlings and
planting them to help re-build the for¬
ests.

Wattles grow very readily on almost
any part of Tasmania. It only requires,
as stated before, for a fire to go over the
glass for the seed to be ready to germin¬
ate, and Tasmanians would do well to
set* that this is done wherever possible,
s> that Australia will not have to import
bark, etc., from countries thousands of
miles away, as is done at the present
time.

I have tried to show that Australia’s
national emblem is not only a very beau¬
tiful plant and tree, but also that it is a
very valuable and useful one as well, and
it is something for Australia to be very
proud of. Any emblem worth notice at
all should be a

Real and Living Expression

of something precious to its people, and
a source of inspiration as well. Think
of this unique flower, complex, and yet
so simple, bending in “golden rain,"
swaying in mystic plumes, twisted in
“golden wreath/' glowing in a million
Huffy spikes, easy to grow, eager to bloom,
both in lowly shrub and stately forest
tree, greatful for good soil, content with
very poor or almost none, fragrant,
friendly, beautiful! Have we not some¬
thing to live up to here?

Some of the Tasmanian varieties of
acacias are:—

Acacia riceana, which is found only in
Tasmania, It is of the very prickly
varieties, the leaves are phyllodes; it has
its leaves in two and sometimes threes,
and the flowers are in sprays of 2 to 2Vz
inches long, with about a dozen balls of

flowers. It is sometimes called weeping
wattle on account of its habit of droop¬
ing with the weight of flowers.

Acacia verticillata js about the most
prickly, sometimes called “prickly wut-
ter" or “prickly Moses/' The leaves
(phyllodes) grow in verticills or rings
round the stem, the flowers are made up
m very many small flowers and form a
spike about one inch long and about Vz
to 5-8 inches thick. The variety will
grow from 20 to 30 feet high.

Acacia dilfusa, another prickly one,
grows only to a small shrub and sprawls
about chiefly, hence its name. The leaves
are phyllodes, the flowers are round balls
containing numerous flowers and come
uJong the stem.

Acacia myrtifolia is, as its name sug¬
gests; the leaves also phyllodes are the
shape or similar to myrtle leaves. It only
grows to two or three feet high. The
flowers are in small spikes of several
balls, the leaves are dark green, and have
a gland near the stem on one of their
edges.

Acacia discolor is one that has true
leaves, but they are not divided nearly as
much as the silver and black wattles. The
flowers are paler in color, anil they branch
a good deal and flower about Easter time.
It is sometimes called river wattle.

Acacia sophorae, boobyalla wattle,
grows near the sea beaches, and has a
spreading habit. Flowers in spring, leaves
or phyllodes have several midribs. but
Jook almost as if they had none, flowers
in spikes about 2 inches long. Makes a
good shelter tree.

Acacia melanoxyIon, “blackwood/* pre¬
viously mentioned. Flowers in spring. The
flowers appear on branch-like stems and
make a very pretty picture, leaves or
phyllodes have four or five midribs or
nerves, and when young the tree shows
the divided true leaves as well as phyl¬
lodes.

Acacia dealbata, or silver wattle, is
known by most people. It flowers in
early spring, and is mentioned earlier. It
has true leaves.

Acacia deacurrens, also previously men¬
tioned, flowers in December. The leaves
ate much darker than silver wattle.

Acacia stricta is one with a narrow leaf
or ph.vllode, about two to three inches
lr? g v' vi , th „ one mi * dril) - Only grows about
4ft. high flowers in spring. Flowers ap
pear chiefly near the leaf stalks. FTas a
dull colored leaf.

Acacia verniciflua is similar to the last
named, but its leaves or phyllodes have
two midribs, and have a varnished ap-

(12)

THE TASMANIAN NATURALIST

pearance. The flowers are similar to the
last-named, and it grows up to nearly 30! t.
high.

Acacia suavcolens. This one is similar
to sLriota, but grows larger. Has leaves,
or phyllodes, up to nearly 6 inches in
length. Has a single midrib, is dull in
color and very narrow, and has ridges
along the stems, especially near a branch
or leaf, giving a triangular appearance.
It flowers in the autumn, and they an-
pear at the base of the leaf in very pretty

buds of a brow’nish color, which open into
a fine spike of Horets or balls up to 2 k
inches long.

Acacia vomeriformis has leaves some¬
thing like the nose of man, and is named
for its similarity to the shape ol the bone
in the nose called the “vomer.” it only
grows up to about one foot high, the
leaves or phyllodes are up to half an inch
long, and pretty balls of flowers at inter¬
vals along the stem. Flowers in spring.

J. C. Breaden.

Some Tasmanian Naturalists.

(1) Cook, Anderson, Nelson.

Introduction.

Tasmania was discovered early in the
fifth decade of the 17th century, ana
not until the opening: years of the last
century did actual settlement take place.
!Tn the time intervening between discov¬
ery and settlement, a number of exp di
ions of British and French nationalities
visited the shores of the island. At¬
tached to most of these expeditions weit
men who had distinguished themselvia
in their pursuit of scientific knowledge
With the sailors who navigated their
. mall ships into these uncharted waters
these men endured hardships which are
t >day inconceivable. At tier long and
perilous voyages they set foot on a
strange shore and labored unstintingly
m the cause « f knowledge. They have
left on record much valuable ground¬
work. which has been the source of in¬
spiration and information for those who
have come after. With the establish
ment of settlement

A New Era Commenced.

but the tradition of the workers before
1803 has never been lost. Occasionally
eminent men of science from overseas
have visited the Island and investigated
c, me aspect of our natural phenomena.
The hard and frequently unrewarded
labor of such researches has m stly
fallen upon the shoulders of a few Tas¬
manians. They have undergone perils
and hardships not incomparable with
those of the earlier period. Readers o
Hubert Mackenzie Johnston's description
< f his geological expedition to the Foutto
and West Const in 1874. can, to a ce -
tain extent, appreciate the difficulties
which these workers had to encounter.
Far from the stimulating influence of
seats of learning, through dense beech
and bauera forests, over sharp ridges
and across precipitous ravines these pm

neers fought their way. In spite of
hardship and difficulty the scientific
workers in Tasmania have made valu¬
able contributions to the store of kno.s*

ledge.

Dutch Expedition. 1642.

The main object of the Dutch exped
tion which discovered Tasmania aid
New Zealand in 1642 was the i-xtcnsi n
of commerce. No doubt the auth rltie.
at Batavia and the Council of Seventeen,
who directed the policy of the Du ch
East India Company, also wished to a 1 d
to their knowledge of the seas to th
south anil east of Cape Loeuwin. In
case the expedition failed to find new
Indies, it might at least discover a n 1
and safer route for their wealth-laden
ships sailing to Hoi.and. Immediate mi
terial gain was uppermost in the minds
of the men who sent Tasman on his voy¬
age of 1642. From the commercial a
pect the expedition was a failure. So
much so that ‘:he opulent counci lorn
never again voted for the expenditur
of so much as

A S’ngle Guilder

to further the cause of South Sea ex
ploration. Nevertheless the expedition
made an extremely important contribu
tion to pure knowledge. Geography
particularly benefited by the disco\erv*
of land lying between 140 and 180 longi¬
tude lower than 40 latitude. Definite
land must be now recorded on maps In
place of fabulous representations of the
southern continent.

Unfortunately the expedition did not
count amongst its company an experi¬
enced observer of natural phenomena.
Tasman and Visscher (a contempory
Dutch geographical authority) was no:
in a position to make scientific observe
turns. It cannot be reasonably expec e I
that the commander of two small s! i a
sailing for mouths in unknown seas.

( 13 )

THE TASMANIAN NATURALIST

should have much opportunity for ex
amining the flora, the fauna, or the rocks
of a strange land that he was in sight
of for a few days. Nevertheless, the
observations which are entered in the
journal of the expedition for these few
days are devoid neither of interest nor
of value. Several boats’ parties made
excursions from the anchorage to ex inl¬
ine the coastline in detail.

The Dutchmen were greatly impie^sed
with the dimensions of some trees that
they found growing near Blackinau’s
Bay (S.E. Coast). The flint-made notch-
ings in the bark of several trees aroused
their curiosity. They correctly assumed
them to be the results of human labor.
None of the aboriginal inhabitants weie
seen, but their presence in the very near
vicinity was suspected by the explorers
These first descriptions of Tasmania ai e
contained in

Captain Tasman’s Reports

from the first to the third of Dec. m’ er,
1642. They are the careful observations
of a practical seaman unaffected by
many of the absurd philosophical no¬
tions of his times. A portion of Tasma¬
nia was now known to the west rn
world, but over a century was to el pse
before another expedition visited her
shores. Meanwhile scientific knowledge
was receiving hitherto undreamt of ad;
ditions, and attracting the attention of
an ever-widening circle of men.

During the lives of these Dutch sail-
tors events were taking place of even
greater importance than the sanguinary
religious wars in which most of the
European peoples were engaged. A feel-
ir»nr of intense distrust of the older con¬
ceptions of science, and particularly the
older methods of enquiry, had long been
manifest among thinking men. Papal
or any other arbitrary authority was
doubted and ridiculed. The upholders
of the older system, the followers of
Aristotle and Aquinas, made strenuous
efforts to stifle the critics at first with
argument, and then with persecution.
But all the profundity ’ of scholastic
knowledge, and all the terrors of the
inquisition failed to stop the new move¬
ment. Astronomy was the first of the
sciences to free itself from the

Shackles o* the Middle Ages.

Copernicus, Kepler, and^ Galileo by
their far-reaching discoveries had not
only advanced the study of the stars,
but had stimulated other branches of
science.

In the early part of the 17th century
two great thinkers arose, the English
Francis Bacon and the French Rene

Descartes. These men have been not
unjustly called “the founders of modern
science.” They each propounded cer¬
tain methods of reasoning, which may be
accounted the most important scientific
weapons ever forged. From their day
science has been able to make an un¬
hindered march ahead.

Three weeks after the discovery of Tas¬
mania Isaac Newton was born. This
great Englishman was destined to do for
physical science what Galileo had done
for astronomy. Ten years later Robert
Boyle laid the foundation of modern
chemistry. In 16453 the Royal Society
was founded. This institution has pro¬
bably exercised a more profound influ¬
ence on the advancement of science than
any other known organisation. During
the next seventy years a steady advance
was made, and then arose another great
scientist in Sweden, Carl von Linn, bet¬
ter known as Linnaeus, evolved a much-
needed system of classification of fos¬
sils, plants, and animals, which wiped
out the confusion of centuries, and is in
use today.

Cook-Nelson-Anderson.

Once again South Sea exploration be¬
gan to exercise men’s minds. This time
the promoters were not Dutch mer¬
chants, who looked only for rich car¬
goes, but the members of the Royal So¬
ciety, who desired only to further the
cause of science. As is well-known, Cap¬
tain James Cook commanded the memor¬
able expedition which

Carried Our Astronomic Observations

at Otaheti, and thence discovered the
eastern coast of Australia, after visit¬
ing New Zealand, Sir Joseph Banks,
an indefatigable worker in botany, and
Dr. Carl Solander, another eminent
botanist, and a student of Linneas, ac¬
companied the expedition. It is unfor¬
tunate that we cannot count these men
as the first scientists to visit our shores.

On his third and last voyage Cook vis¬
ited Tasmania. David Nelson, a Kew
gardener, and a botanist of merit, ac¬
companied the expedition in the capacity
of collector. Little is known of Nel¬
son. but he is described as “one of the
quietest fellows in nature, and seems
very attentive,” by one of Cook’s assist¬
ants. Apparently he was in the ser¬
vice of Banks.

After a rough voyage from Kerguelen
Island, lasting nearly a month. Cook’s
two ships, the Resolution and Discov¬
ery. came to anchor in Adventure Bay
( January, 1777). Cook, with character¬
istic industry, employed the four days
at his disposal on the

( 14 )

THE TASMANIAN NATURALIST

Shores of South Bruny.

to great advantage. Through his friend¬
ly intercourse with the natives he was
able to learn something of their cus¬
tom e. His notes on the aboriginal race
are the first contribution to Tasmaniai.
anthropology. Those subjects, of which
Cook possessed expert knowledge,
claimed most of his attention. His
work included astronomic observations,
the determination of latitude and longi¬
tude. the rise and fall of the tide, and
the determination of magnetic variation.
Four days was a very narrow limit to
impose on such a worker.

Nelson also took full advantage of the
unique opportunity of being the first bot¬
anist to visit Tasmania. With the as¬
sistance of William Anderson (the sur¬
geon of the Resolution) he made a con¬
siderable collection of plants, which
eventually found their way to the Brit¬
ish Museum. Amongst other specimens
collected were some twigs of stringy
hark (K. obliqua), which were describ¬
ed by the French naturalist, L'Hertier,
as belonging to the genus eucalptus.
Thus was this important member of Tas¬
manian flora first noted. Nelson also
described two other plants.

Although of short duration, the visit
was most profitable from the scientific
point of view. Cook was destined never
to reach home. He was killed by the
natives at the Sandwich Islands, Later
in the voyage Nelson returned to Eng¬
land safely. He joined Bligh in the
capacity of collector on the famous

Voyage of the Bounty

in 1788, when he again visited Adventure
Bay for a few days. With Bligh he was
set adrift bv the mutinous crew of the
Bounty. The exposure of the boat voy¬
age proved too much for him, and he
died at Timor in 1780. Bligh paid n
high tribute to his admirable qualities.
That roekv landmark at .Adventure Bay
is nppropirately named Nelson’s Look¬
out. after this early pioneer naturalist.

(2) Labillardiere.

employed by scientists and thinkers of
trying to explain difficult questions cf
origins by argument was faulty. His
method was to study things as they
are, and by means of historical facts
determine how they cam^ io be. In a
great work on human institutions he
applied his teaching, which is known
as the historical or comparative method.
Of such importance is this method in
all scientific studies, that the year of
the publication of his work (174S) is
almost an epoch in the history of
science. At the same time a French
nobleman, Comte de Buffon, was the
leading study of botany and zoology in
France. He was the first to apply this
historical method to scientific research.
Buffon’s life’s work in observations laid
the foundations which the biologists of
the next century were to build on.

Botany was receiving more and more
attention, and the work of Linnaeus was
carried on by Bernard de Jussieu. To¬
wards the end of the century another
great biologist. Georges Cuvier, was be¬
ginning to make discoveries which led
to the' study of palaeontology as a
separate science. Among her chemists.
France possessed one of the greatest
men of his time, Antoine Laurent Laroi-
sier He enunciated the principle upon
which chemistry as an exact science
rests. “That in the process of chemical
action matter is neither created nor
destroyed.” Laplace, the contemporary
astronomer, was discovering new stars
and adding to man’s knowledge of the
laws of the universe.

It was the good fortune of these men
that the successive governments of
France, ancient regime, republican and
imperial, gave them encouragement and
assistance. During the “Reign of Ter¬
ror.” in common with thousands of
others, their lives were often in danger,
but Lavoisier was the only one of the
few who sacrificed, the memorable
words of his sentence being, “The re¬
public has no need of scientists.”

(a) The Progress of Science in France.

In the latter part of the eighteenth
century a brilliant school of scientists
arose in France. They forged new
weapons in initiating new methods
of investigation, and they made ’emark-
able contributions to the stock of know¬
ledge. Tn astronomy, physics, and
mathematics, in biology, and chemistry 4
they almost led the world. A famous
French lawyer, Moniesquieu, demon
strated that the method then frequently

The influence of the French scientists
extended far outside the frontiers of
their country. As well as influencing
the advance of thought in other coun¬
tries. collectors and observers visited
many little-known lands. In parts of
Africa and America they were pioneer
observers of natural phenomena. In
Tasmania their opportunity was unique,
and one of them at least has rightly
earned a. lasting place in the record
of our scientific records.

(15)

THE TASMANIAN NATURALIST

(JB) JAQUES JIILdEN LABILLAR-
DIERE.

The excitement of the revolution in
no way abated the interest of the
French nation in the disappearance of
their illustrious navigator. La Perouic.
The years 1789 and 1190 passed away,
but nothing was heard of his expedi¬
tion, which had left Sydney for a Pacific
cruise in 1788.

At last in 1791 the French Govern¬
ment despatched Admiral Bruny
D’Entrecastaux with two ships, La
Recherche, and L’Esperance, to the Pa¬
cific to solve the mystery of the sea.
A small scientific staff was attached to
the expedition, the chief naturalist be
ing Jaques JuJien Labillardiere. He was
assisted by three other observers, l)es-
champs, Perin, and La Haye. An as¬
tronomer namer Bertrand also accom¬
panied the expedition, but it seems that
he remained at the Cape of Good Hope.
We know little of Labillardiere, bu-
that he was a scientist of no mean or¬
der is clearly seen by his accomplish
meets. Probably he was one of the en¬
thusiasts who worked with such men
as Bufifon or Jussieu. The expedition
arrivea off the south of Tasmania in
April, 1792, and by a memorable error
discovered the long passage of water
between Bruny Island and the main¬
land. Over a month of exploration work
was carried on by means of boat ex¬
peditions, which extended as far as tli#
present Risdon cove on the east L#»-
went. iaUJ i

As the boat expeditions were making
entirely new discoveries, Labillardiere and
his fellow naturalists were given unique
opportunitie sto perfoim original work.
David Nelson and Surgeon Anderson, n
Cook’s third voyage, were limited to the
shores of Adventure Bay, but these men
were able to examine the flora and fauna
for nearly 100 miles of hitherto unknown
coast line.

The members of expeditions came into
contact with the aboriginal inhabitants
who had their middins in the hays and
beaches of shores of D’Entrecasteaux
Channel. Labflliardiere gives several
highly interesting descriptions of his meet¬
ings and intercourse with the natives. Tt,
is pleasing to record that the French
preserved the friendliest relations with
these primitive people. Tt is impossible
to give in detail Lnbillardiere’s account in
such an outline but several incidents he
describes worth relating. He was verv
surprised that he found the utmost diffi¬

culty in persuading one native to ex¬
change a kangaroo skin for some articles
of European clothing. Of .. group of four
native girls lie interviewed, he says: —
"No doubt we lost much by not under¬
standing the language of these natives,
tor one of the girls »u.d a good deal to
us; ,she talked a long time with extra¬
ordinary volubility, though she must have
perceived we could not understand
meaning; no matter, she must talk. The
others attempted more than once to charm
us by songs, with the modulation of such
I was singularly struck, from great
analogy of the tunes to those of the Arabs
of Asia Minor.”

Labillardiere very fortunately ^ives us
a great deal of detail concerning the
aborigines. He saw more of them in their
natural state than any other observer, and
we have every reason t< believe that in
the record of his observations he main¬
tained a high degree of accuracy. Tn
the collection and describing of the flora
he met we find Labillardiere doing his best
work.

Among the many Tasmanian species
that he first, described are some of nnr
best known bush plants. Blue gum (E.
globulus), peppermint gum (E. amygda-
lina), white gum (E. viminalis), sheoke
(Casuarina quadrivalris). lancewood (Erio-
stemon squameus). laurel f Anontenis glan-
dulus), purple heather (Tetratheca glan-
dulosa), and the white flag (Dipharrhena
moroea).

Tt is impossible for students of botany
not to envy Labillardiere tor the oppor¬
tunity he had of viewing the forests on
the banks of the TTuon in then* natural
state. The expedition failed to find the
missing navigator, but the scientific work
done by its members in Tasmania was very
considerable. L*ibil1ardiei*e , s observations
and studies of the aboriginal peoples have
been, and still are. af value to students
of anthropology. His botanical work pre¬
pared the way for the great British botal-
ist. Robert Brown, who was to visit the
islands a few years later.^ He also de-
ser'bed a number of Hie animals and fish.
A brief extract from the ionrnnl of the
vovavo rrives us 'n : rh*a of tilo laborR of
Labillardiere and bis ‘ellow scientists.

“The naturalists have made precious
harvests in cverv department. Several
new plants, unknown fish birds never
before described, and others which, with¬
out different as to species from those of
neighboring countries, are. however, of
verv curious varieties, have enriched their
collection. wh-Vh seems to have been
more abundant in this southern mart of
Vow Holland than w-w ifmt made by Mr.
Anderson in Adventure Bay.”

( 16 )

Your Safe Guide for Shopping:

“Brownells for Value”

Test the Statement when next you

Dress Goods
Wash Fabrics
Household Linens
Blankets
Napery Items
Gloves, Hosiery
Laces, Ribbons
Veilings, Neckwear
Handkerchiefs

Perfumes, Cosmetics
Haberdashery
High-class Millinery
Ready-to-Wear Hats
Stylish Frocks
Costumes, Coats
Blouses, Skirts and
Fur Goods
Smart Footwear

have to buy

Corsets, and Ladies’
Underclothing
Men’s and Boys*
Suits and Mercery
Curtains, Blinds
Fancy Furnishings
Carpets, Linoleums
New Chinaware
Furniture, Bedding

ANTIQUES

BROWNELLS have a Special Department devoted to the
sale and collection of Antiques, including Oak, Rosewood,
Cedar and Mahogany Furniture; Cut Glass, China, Brass
and Silver Specialties.

Old Furniture repaired, re-polished and re-upholstered by
expert workmen.

Brownells are Sole Agents in Tasmania for

Newby & Evans’ Player Pianos

High-grade Instruments that are yielding the fullest musical satisfaction and
enjoyment in many Tasmanian Homes

CASH PRICE - - £195

BROWNELLS are also the Sole Tasmanian Agents for the renowned McCall
Printed Patterns and Publications. Special department installed in centre of Ground Floor.

BROWNELLS are also the Sole Agents in the Capital City for the Famous
Gossard Front Lacing Corsets and Brassieres, of which the latest models are stocked
in a fine representative assortment.

A BUSY MAIL ORDER BRANCH CATERS FOR THE
REQUIREMENTS OF COUNTRY RESIDENTS, TO WHOM
MERCHANDISE IS FORWARDED, CARRIAGE PAID.

In the Mail Order Department AUNT EDNA is the Famous Lady Shopper

BROWNELLS LIMITED

“London House” (Founded 1836)

98-108 LIVERPOOL STREET - - HOBART

Metropolitan College Pty. Ltd.

(Commercial and Domestic Art Subjects)

THE METROPOLITAN COLLEGE IS THE LARGEST
AND BEST EQUIPPED COMMERCIAL COLLEGE IN
TASMANIA.

At the beginning of January the whole of the existing
typewriter plant was re-placed with new machines.
Instruction is given on every standard typewriter, in
addition to which students are taught to operate the
Burroughs Calculating Machine and the latest Remington
Accounting Machine.

We secure positions for every one of our graduates, and
the welfare of our students is our first consideration.

We have day and evening classes in all subjects, including:

Shorthand

Typewriting

Book-keeping

English

. Arithmetic

Accountancy
Auditing

f , Commercial Law

The Term starts Irom date of commencement. Send for our Prospectus.

V,*

Special Classes are conducted for the State and Commonwealth Public Service
(Typistes) Examination, and our results are always highly satisfactory. Our students
secured both first and second places in the last two examinations, and we invite comparison.

We present students for the Intermediate and Final Examinations of the Federal
Institute of Accountants, Australasian Corporation of Public Accountants, Commonwealth
Institute of Accountants, and the Australasian Institute of Secretaries.

DOMESTIC ART SUBJECTS

Classes in Dressmaking, Dresscutting and Designing are conducted at
Launceston, Longford and Deloraine, in addition to those at the Hobart
College.

FEES AND FULL PARTICULARS GLADLY SUPPLIED ON APPLICATION

METROPOLITAN COLLEGE PTY. LTD.

(Managing Director: THOS. LAYTON, A.I.C.A., Etc.)

Head Office and College:

“Macquarie House,” 151 Macquarie Street, HOBART

P.O. Box 504 F ’Phone : Central 720

Branch Colleges: LAUNCESTON, LONGFORD & DELORAINE