New Year in Sydney

First, here are some samples of a Sydney New Year's Eve, taken from expensive seats on Pinchgut, two years back. This year, we and our standard NYE friends will dine at a quiet restaurant away from the lowing herd, then walk back to our house to see the New Year in, on a north-facing balcony, looking away from the glows in the sky. After almost 50 years of harbour fireworks (the first we saw were in 1970), we don't like the discomfort and the heaving crowds.

Beforehand

Things happened to amuse the waiting crowds. Remember the bridge, because it plays a role.

The sun set, but it wasn't 9 pm yet.

Finally, the show began. Look for the bridge and the Opera House.

Look for the bridge and the Opera House. These are our tribal icons.

Among the guests on Pinchgut were two Scots couples who come out each year for the fireworks on the harbour. I fear they may have had to find a new vantage point this year, as the restaurant on the island seems to have disappeared.  Our Australian celebration of New Year's Day owes a lot to our Scots heritage.  Perhaps I am a biased observer.  As my surname implies, my ancestors were Scots.  My family has been here since early colonial days, but we still keep many of the old traditions intact.

Even in my generation, there has always been at least one piper in the family to welcome in the New Year with a skirl, and the bagpipe remains my favourite solo instrument, for I spent my earliest New Year's Eves, standing directly beneath my father's chanter (that's the lowest pipe, the one you twiddle on), taking in the sound and the smell of the pipes.

Perhaps I will learn to play the pipes when I retire.  I will be in good company if I do, for I know of just the pipe band for me, made up entirely of old and retired ‘Scots’, most with broad Australian accents.  Some traditions die hard, even under an Antipodean sun.

Others may celebrate their New Year's Day by nothing more than a day at the beach, or around a suburban backyard pool.  Still, some hardy traditional types will spend the day at a Highland Gathering, engaging in all sorts of strange activities like tossing the caber and wild dancing to pipes that serve to remind them of the hangover they still bear from the night before.

Traditionally, anybody can be a Scot on that day.  My father knew a champion piper called Colin Campbell who was, as it happens, one of the original Australians.  In those days, whites would stress further that Colin was a ‘full-blooded aboriginal’.  Be that as it may, he would appear each year in the New Year's Day piping competitions to play his own spirited rendition of ‘A man's a man for a'that’, and often to take prizes for his playing.  Those who know their Burns, of course, will see Colin's point . . .

But Sydney has always had its unusual Scots.  A hundred years ago, a Chinese merchant of Sydney, one Quong Tart by name, was popularly known to one and all as ‘Quong Tartan’.  He came to the Australian goldfields as a small boy, and was taught English by Scots people, so his accent was well suited to his nickname.  Historical accounts mention that he was an accomplished reciter of the poems of Robbie Burns, including, I imagine, ‘A man's a man for a'that’.

One of the things which strikes tourists about Sydney is the huge range of faces on the street, but this is by no means new.  Now, we call it ‘multiculturalism’, but it used to happen a hundred years ago as well.  Here is what ‘James O'Connell’ wrote in 1836, preserving his spelling:

In George street, the grand thoroughfare, the visiter is amused with the motley group of divers nations, kindreds, and tongues that he encounters.  New Holland is less exclusively the residence of convicts than the reader may have imagined.  Settlers and visiters from all portions of the globe — Spaniards, Frenchmen, Englishmen, Americans, Chinese, Malays, Kanakas or South Sea Islanders, the latter arriving in whale ships, add variety to a scene which, without them, would be varied enough.

‘O'Connell’ was an escaped convict who had clearly spent several New Year's days here before he escaped to Ponape (Pohnpei) in what was then the Caroline Islands, and later to the United States, but let us stay with the present, for now.

Other Australians will spend New Year's Day in the bush.  No, not in A bush, but in the bush.  That is, in what other lands might call a wilderness, a forest, a jungle, or even a heath.  To us, these are all one and the same: they are all ‘bush’.  Where other nations go hiking or back-packing, we go bush-walking.  Last century, we never had highwaymen, but we always had our bushrangers.  We took the word "bushranger" from the Americans, who used it to mean anybody who roamed freely through the forests, but it soon took on the meaning of an armed robber.

‘Bush’ can also mean anything rural, not of the city, as in ‘the city or the bush’, or as in a classic ribald poem, ‘The Bastard from the Bush’, but mainly it refers to those patches of native Australian vegetation which are to be found, even in the middle of a city of nearly four million people like Sydney.

New Year's Day will be a hot and listless high summer day, so the sensible thing to do is to find a shady spot beside a creek, to swim a bit, to eat a bit, to drink a bit, to relax and enjoy the quietness.  One of the joys of Sydney is that you can find clean cool water in a quiet gully, within an hour of the very centre of the city.  The most preferred housing sites have a harbour view, closely followed by those looking over, and surrounded by, bush.

Of course, this can also a drawback, for those patches of bush can flare up into cruel bushfires, but that is something most people prefer not to think about on New Year's Day.  It is high summer, there is cricket on TV, beer in the fridge, and tomorrow will be a time to relax, at least for now.

I might just spend a few days in the bush. After all, ours is an evolving culture.

Still, bliadhna mhath ur.

Frogging

This went out originally as an ABC Radio National broadcast on Ockham's Razor. It has been edited to disguise locations.

It is a warm and moonless Saturday night.  It is raining, the cloud is down so low on the headland that it qualifies legally and scientifically as mist, and I am wandering around in the dark through dense heathland, half a kilometre from home, with the rain soaking through my broad-brimmed hat, and running down my neck.  Every so often, I stop and shout ‘FROG!’ as loudly as I can.  Then I raise my dripping hat to hear if anything answers.

It is probably fair to ask whether these are the actions of a sane man.  I say they are, but then I know what I am doing.  Or that is my story, at any rate, and I would like to stress here my non-membership of that strange breed, the compulsive froggers, people who sometimes care more for frogs and toads than they do for humans.

I know that I retain my sense of proportion, my sanity, for out there, alone in the dark, I am still rational enough to ask myself what I am doing there.

I am on a headland near Sydney Harbour, in a large patch of bush where there are three, or possibly four species of frog.  After steady rain, there will be equally steady seepage out of the sandy soil for some weeks, and the frogs have a chance to rebuild their numbers.  They gather near the trickling water, they call, and they mate.  Their tadpoles will hatch a few days later and rush through a hurried childhood into premature adolescence, before they join their parents on the drying land.

As a child, I collected tadpoles once or twice in a glass jar and brought them home, but I never succeeded in growing any up to be frogs.  As a young adult, I maintained a genial interest in frogs.  I learned to feed the tadpoles on lettuce, to get them to the adult stage.  Most importantly, I learned to provide them with a rock to rest on, a way out of the water.  Emergent frogs have lungs, not gills, and they will drown if they cannot scramble out.

Many years ago, as a young biology teacher, I acquired by devious means a lockable glass-fronted cupboard, designed for chemical storage.  I bolted it to a corridor wall where passing students could look in.  I bought a narrow glass tank and went through a number of frog-breeding cycles over several years, but I was still not a compulsive frogger.  I just thought it was good for students to have a small ‘zoo’ to look at.  Tadpoles and frogs were a major part of what happened there, along with assorted invertebrates and static demonstrations, but I was definitely not a compulsive frogger.

Later, I moved house, and we soon found that frogs had joined us in our garden.  We got up one rainy morning to find that we had a frothy mass of frog eggs in plastic bowl that lay abandoned in the garden.  Delighted, I dug a small pond, and transferred the eggs across.  Soon after, when I had to build some new stairs and a landing into the backyard, I constructed a much larger pond in the wasted space underneath the stairs.  Friends thought this a little eccentric, but I knew I was still not a compulsive frogger.  Even the friends could see that, when I explained it to them.

Some years later still, I found myself working in a museum, and I was cajoled into working on a project called Frog Watch, that involved both frogs and computers.  I was involved more as a writer and computer person, though I found myself getting more involved in froggy things.  But still I resisted the temptation to become a compulsive frogger.

I met quite a few compulsive froggers while I was there.  One of them noticed a small population of tadpoles sharing a pool with some mosquito fish.  This surprised him, for mosquito fishes will attack most tadpoles, and eat them, working up from the tail.  Most people would have passed on to other things, but this frogger thought about it, and concluded that the tadpole must taste rather awful.  A true man of science, he tried eating several of the raw tadpoles.  They tasted vile, a discovery which may have waited forever, but for the dedicated commitment of this compulsive frogger.

I met a fellow worker, who kept several pet frogs in a tank in his office, where they responded every time his phone rang.  Later, I edited a frog book for another colleague, who kept a one-eyed tree frog in his workshop (it lost the other eye when a truck ran over it, but my colleague nursed it back to health).  I knew I was still not a compulsive frogger, not by any of the rational standards that I could construct.

Pseudophryne australis, otherwise the Sydney red-crowned toadlet.
CC BY-SA 3.0, 
https://commons.wikimedia.org/w/index.php?curid=1185340

Then I moved house again.  Soon I started to notice the several frogs living around my house.  I bought tapes to identify them (you ‘earball’ frogs rather than eyeballing them), and I started to learn how to provoke certain species to call.  Then one day I found a small frog in my front yard, did a quick double-take.

With delight, I realised that the seepage drain near my front gate was home to a member of an endangered species, a Sydney Red-crowned Toadlet.  I was still not a compulsive frogger, but now I was distinctly interested.

Since then, I have been trying to map the frog's distribution in the local area by going out in wet weather and listening for the toadlet's distinctive call.  Somebody in Canberra told me once that the Corroboree Frog, another member of the same genus, will answer if a male human voice bellows ‘FROG!’ nearby.  Testing that theory is what leads me out into the wilderness on damp still nights, shouting in the dark.  That and finding out just how healthy the local population is, but I am still not a compulsive frogger.

My little toadlet lives in some two hundred pockets of land around Sydney.  In all likelihood, each population carries different genes, but there is no flow of genes between the different localities.  Each group is an isolated remnant.  If any group dies, it will not be replaced by new colonists moving in, for they cannot swim over the salt water of the harbour.  There is no bridge for them to use, and pioneers cannot hop over the 5 kilometres of settled ground to get here from the next pocket.

The toadlet's distinctive  underbelly.
By Tnarg 12345 at the English language Wikipedia, CC BY-SA
3.0, https://commons.wikimedia.org/w/index.php?curid=2652554

If any isolated group dies out, its small part of the genetic diversity dies with it.  The special genes that they alone may have are no longer available to the population as a whole.

It is a simple enough principle: even the ancient Romans understood it, when they coined the phrase ‘Divide et impera’ — divide and rule.  It is a cold implacable logical law, and its operation may one day wipe out all of the toadlets.

But why should we worry about one little frog, when there are hundreds of other species in Australia?  Many years ago, Paul Ehrlich taught us that we should think of an ecosystem as rather like an aeroplane which can lose a few bits and still fly.

I prefer to see an ecosystem as a steel bridge.  You can take one rivet away from a bridge, and nothing will happen.  You can remove another rivet, and the bridge will be as steady as ever.  You may even take some more, and still do no harm.  But somewhere along the way, you will take out one rivet too many, and the bridge will come tumbling down.  Ecosystems are robust, they can manage without some of the key species, but sooner or later, they start falling apart.

Biodiversity in a species works the same way.  Eliminate a few unusual genes, and no harm will arise, not yet.  Take a few more rare genes away, and there will still be no problem.  Sooner or later, though, some other change will mean that one of those eliminated genes will be needed.  By then, it won't be there, because the gene's minders have died, and the gene has died with them.  All over Australia, the frogs and toads are reminding us, calling ‘rivet, rivet’, but nobody cares, for the frogs' bridge is still standing.  It sags a bit, it may sway perilously from time to time, but it is still there.

It is a warm and moonless Saturday night.  It is raining, the cloud is down so low on the headland that it qualifies legally and scientifically as mist, and I am wandering around in the dark through dense heathland, half a kilometre from home, with the rain soaking through my broad-brimmed hat, and running down my neck.  Every so often, I stop and shout ‘FROG!’ as loudly as I can.  Then I raise my dripping hat to hear if anything answers.

I know now why I am there in the dripping mist.  I am still not a compulsive frogger, but I think I understand them now.

Food preservation

Here's a small sample from Not Your Usual Science, which is now finished, but getting a last polish. That will take a while, as it ended up at 460,000 words. It will be out on Kindle in a month or two.

The illustrations are from a recent visit to Sri Lanka, where I saw fish being sun-dried.

Negombo beach, tuna.

Nobody ever sat down and thought “today, I will invent technology and change society”. It was more likely to be a matter of certain aspects of technology emerging, after which people used the new ideas, and only realised later that they had changed their society. Even more likely, they found a new way, used it, and changed their habits, which in turn changed society.

Before the development of agriculture, people had to live a nomadic life, moving after the food, following the seasons. Once they had ways of growing food near a permanent home, they could settle in one place, but then they needed ways to preserve and/or store food, to stop it going bad.

A closer view of the tuna

The process would have begun slowly, because even nomads knew how to smoke meat over a slow fire, or use sunlight to make beef jerky. Fish could also be dried or smoked. Before people knew about germs, salting was a good way to stop germs growing on meat.

Water can flow out of living cells and it can also flow back in through the cell membranes. High salt concentrations outside a cell stop water going back in, so any microbes in salted food soon dry up and die. When beef or other meat is dried, the salts in the meat are left behind, and once again, the salt levels stop bacteria and fungi from growing. (If you want to know what is going on here, the key word is osmosis, but right now, we are discussing history.)

Bees have used the drying method for millions of years, collecting nectar and fanning it to evaporate off most of the water, changing the nectar to honey. Spores and germs that fall into the honey simply cannot grow. When sugar cane is crushed, the juice is boiled and this concentrates the solution to stop any fungi or bacteria surviving in it.

All sorts of fish are dried.

By good luck, heating the cane juice also destroys a natural enzyme in the sugar cane which breaks the sucrose molecule down into simpler sugar molecules which are less useful, and the whole sugar industry depends on destroying this enzyme.

Islamic societies around the Mediterranean followed to a greater or lesser extent the teaching in the Quran that drinking alcohol was wrong, but even pious Muslims still liked cooling drinks. Highly concentrated fruit juice and sugar would keep forever, as nothing could live in it, but this cordial could be mixed with cool water to make a pleasant drink.

They are mainly carried inland and sold. Without fish, the
inland folk would have an iodine deficiency and goitre.
In a very real sense, the population depends on dried fish.

When the Egyptians preserved dead bodies, they used a similar method, but they replaced ordinary salt with natron, a mixture of sodium carbonate and bicarbonate which, as we have seen, was also used in glass making. The mummies would have tasted better with salt, but as nobody planned to eat them, natron was fine.

All the same, it would be reasonable to suspect that the Egyptians knew about salting meat before they made mummies, which would mean they must have started salting meat at least 4500 years ago.

Whatever method is used, preservation either sets out to kill the food-spoiling microbes, or to slow them down, making the food last longer. Warming up food makes a perfect environment for germs to multiply, and “food poisoning” often begins with warmed-up food being set aside and then heated again.

Geoffrey Chaucer was an English poet and scholar who died in 1400, as the Middle Ages came to an end, but he knew all about this danger. In his Canterbury Tales, Chaucer has a character accuse a cook of ignoring this risk. The Jack of Dover mentioned here was almost certainly a pie of some sort:

And many a Jakke of Dovere hastow soold,
That hath been twies hoot and twies coold.

 In more modern (but similar) language, this says:

And many a Jack of Dover hast thou sold,
That had been twice hot and twice cold.

Refrigeration is a good way of slowing down germs, but as Chaucer knew, more than 600 years ago, the cook’s habit of re-warming food made it potentially deadly. Unlike Chaucer, we realise that repeated warming of food can increase the number of bacteria to dangerous levels, but even without knowing about germs, Chaucer knew that reheated food was dangerous.

We can look at a food preservation method today and see the science which lies behind it, but each of the methods must have been originally discovered by chance, perhaps when an animal drowned in a brine pond, and was later found, free of rot.

Food left too long over a low fire may have been dried or smoked, wheat and barley stored in pots in hot dry places stayed dry and undamaged, and so on. Freezing of dead animals caught in a snowdrift may have preserved their meat, but looking into this actually killed one scientist, Francis Bacon, also known as Lord Verulam:

Mr Hobbs told me that the cause of his Lordship’s death was trying an Experiment … it came into my Lord’s thoughts, why flesh might not be preserved in snow, as in Salt. They … bought a Hen, and made the woman exenterate it, and then stuffed the body with Snow, and my Lord did help doe it himselfe. The snow so chilled him that he fell immediately ill … they put him into a good bed, warmed with a Panne, but it was a damp bed that had not been layn-in in about a yeare before, which gave him such a colde that in 2 or 3 dayes … he dyed of Suffocation.
— John Aubrey, discussing Francis Bacon (1561 – 1626), Aubrey’s Brief Lives, 179.

Whichever way the food was preserved, even without knowing anything about the spores, bacteria or fungi, humans stopped their food spoiling. The result was that people were able to live through bad seasons or times when there was no food to be had. They were also able to store food such as turnips or hay to keep animals alive, and dried foods were light enough to carry on long journeys.

Unfortunately, some preservation methods also destroyed any vitamins that might have been in the foods. Sailors and other travellers who tried to live on salt meat and ship’s biscuit (a very dry sort of bread) risked developing ‘disease’, as scurvy used to be called. On short voyages, the passengers and crew had enough vitamin reserves in their bodies to stay fairly healthy, but as voyages grew longer, people began to sicken, or even die, killed by the preserved food they thought was keeping them alive.

Pickling with a mixture of salt and vinegar can stop vegetables spoiling. Salt does not destroy vitamin C, the cure for scurvy. Salt meat has no vitamin C because the original meat had none, but pickled cabbage, sauerkraut, still has most of the vitamin C found in the original cabbage. Lime juice was boiled to a concentrated germ-resistant syrup. That usually kept some of its vitamin C, so long as the lime juice had not been boiled in copper pots. Copper surfaces are very good at destroying the vitamin.

Preserved foods allowed Europeans to discover the whole world and then dominate it. It was a mixed blessing, when you consider how they treated those they dominated!

Bushfire backgrounder

Bushfires are a part of high summer in Australia. In winter each year, Australians carry out control burns, small fires aimed at reducing the amount of standing fuel. These may help to contain the fires or stop them, but given the wrong weather, no amount of control burning can stop fires happening somewhere. The science is against any other outcome.

A note first about terms: in Australian English, ‘bush’ is what others might call forest, heath or scrub. The term was brought to Australia by early settlers who had previously lived and worked in North America, so this quintessentially Australian term is in fact an early American import! A ‘bushfire’ is a fire running wild in the bush. 

Many botanists in the past have been forced to change their research to ‘bushfire regeneration’ after their plots were burned out, and the cost of fires has meant that there has been a great deal of research on the topic.

First, let us consider the biology of bushfire in Australia. Fire is a natural part of the bush cycle, so the natural environment should survive fairly well, just so long as there is no heavy rain, too soon afterwards. That is why the fire fighters will concentrate on saving property and lives.

They will fight fire with fire, knowing that what they burn deliberately will grow back again, refreshed by the flames. Australia’s bush, after all, lived with fire for many millions of years, long before humans came here. The bush will grow back after the fires have done their worst.

Next, let us consider the geology and geography of urban Sydney bushfires. When the first Europeans reached Australia in 1788, they settled in what is now Sydney, either on flat land near the sea or on the ridges.

Sydney sits on a bed of sandstone, two to three hundred metres thick, with joints running north-south and east-west. It was laid down in a Triassic delta, rather like Bangladesh today, with a huge river braiding back and forth, washing out the finest minerals, the clay and other mineral-rich sediments, and leaving just the quartz grains behind. The grains were rounded, and had probably been in an earlier sandstone somewhere else, but they settled where Sydney is now, almost 200 million years ago, waiting to play their part in shaping modern Sydney.

Some of the sandstone beds are better bonded than the others within this ‘Hawkesbury sandstone’, but they are otherwise pretty much the same, right through the deposit. (Hawkesbury, in case you are wondering, was a minor 18th century English politician who had a local river named after him. The stone was later named after the river.)

In the last Ice Age, the sea level around Australia was much lower, due to all the water tied up in the northern glaciers. Then, today’s Sydney Harbour was a river valley, shaped by the jointing pattern in the sandstone. Joints, planes of weakness in the stone, were eroded into crevices which became valleys, with the more resistant sandstone forming ridges. Later, the sea level rose, creating a ‘drowned river valley’ with a characteristic fern leaf shape, the modern Sydney Harbour. A few of the higher ridges have a shale capping which offered rather better soil than the sand which derives from sandstone.

The first whites settled on the coast, then headed (a) for the flat land of the ridges, where roads were easier to build, and (b) for the richer soil on the shale-capped ridges. First, they built small farms and market gardens, then roads were built to service these, and soon the residences followed, as a young city grew. Down in the valleys, close to the sea, the bush was left alone. It was too hard to build roads down to there, and so people left it alone. Even today, much of the valley bush is preserved, with homes sitting on the ridges above: a sure recipe for trouble, because heat and flames rise.

Fuel builds up in the bush over a period of years. Gum trees shed their bark, branches and leaves, smaller shrubs in the under-storey die and are replaced by others, and after a few years of recovery, the lowest three metres or so is a closely packed mass of dead and drying twigs. Until they break and fall, these pieces of finely divided wood rot very little in the dry bush, and even on the forest floor, rotting is a slow business, for the sandy soil drains fast after rain. Heath regenerates fast.

Some of them can be ready to burn again, just six months after a major fire. Other areas can take ten to twenty years to be ready for a major burn. As a general rule, after 40 or 50 years, any area at all will be ready to sustain a ‘blow-up fire’.

Now for the physics of bushfires in Australia. When any fire starts, it begins very slowly. It takes time to develop from a maker of smoky wisps into a maker of misery. The dangerous fire is one that roars and gusts through the tree tops, the crowns of the trees, a firestorm traveling at 50 kilometres an hour or more, leaping ahead of itself, and destroying all in its path.

Crowning fires can cross 400 metres of open water, as the sparks and burning rubbish fly up in the roaring flames, and then tumble down on the other side. Any footage you see on your local TV will be of these crowning wildfires.

You will see flames gouting 30 metres or more into the air, searing the upper branches of gum trees, leaping across the fire breaks, and almost impossible to control until the weather improves.

Now let us look at the question of weather and bushfires. The weather is the last factor in the bushfire equation. At the moment, we have hot dry nor-westers, gusting at up to 50 knots, pushing the fires downhill as well as up. Usually, a fire front can be beaten as it crests a ridge.

Fires go fast uphill and slow downhill, but they do run downhill. On the forward side of any advancing fire, you will find a wind blowing towards the flames at the front of the fire. If you can set small fires on the far side of a ridge, they will gather strength and rush up, sucked in by the fire wind from the blaze on the other side, until the small fires meet the major fire coming the other way.

In this style of fire-fighting, the major fire limps over the ridge, only to find that most of the fuel in its path has already been burned. Starved, it falters like a wounded beast, and puny men and women rush in to attack it with sprays and hoses. But with high winds, this ploy is too dangerous to attempt, as the fire lighters in its path could easily be over-run, as it leaps over the fire break they have just made.

Within hours of the fire, the seeds will be dropping from the woody fruits of the she-oaks, Hakeas and Banksias, and the trunks and underground stems of other plants will already be starting to shoot. In three weeks, there will be green all over the bush. In time, the bush will recover, and so will the animals. The homes can be rebuilt, and lives, so long as they have not been lost, will go on. It is all part of the natural cycle. The animals will take longer, but some will survive, and others will move in from unburnt areas, but recovery is a slow natural cycle.

Inventing writing

Another sample from Not Your Usual Science. Be patient... I got side-tracked to do an essay on poisons (one of my favourite topics) that looks like turning into a book.

So since we are talking about writing, there were a few conditions that would need to be met before writing caught on. As a rule, nomads would not wish to make or carry around records, especially when they were written on heavy clay tablets. So people probably needed something to write on, something to write with, and a useful place where the written records could be kept. Inscribed stones might appear, but unless there were other uses, the whole writing thing might be a bit of a flash in the pan.

The Sumerians explained the invention of writing with a sort of fairy tale about a messenger who was so tired when he reached the court of a distant ruler that he could not deliver his message from the king of Uruk. Hearing this, the Sumerian king took a piece of clay, flattened it, and wrote a message on it.

That story has a few sizable holes in it. How would the person receiving the message know what the symbols meant? Then again, what can we expect in a tale about events that happened so long ago, especially when it was probably not written down?

Hieroglyphs. [Christine Macinnis]

The Egyptians said the god Thoth (the scribe and historian of the gods) invented hieroglyphs; the Sumerians either credited the unnamed king who wrote to Uruk — or the god Enlil. The Assyrians and Babylonians said the god Nabu was the inventor, while the Mayans said they owed their writing system to the supreme deity Itzamna who was a shaman, a sorcerer, and creator of the world.

More plausibly, Chinese tradition says writing was invented by a sage called Ts’ang Chieh, a minister to the legendary Huang Ti (the Yellow Emperor).

How many of these can you "read"?

Some writing used characters to represent syllables, other writing systems used a symbol just to mean a letter-sound (as we do in English), while still others used a symbol to mean a word or idea, as happens in Chinese.

These word/idea symbols are called ideograms or logograms (meaning each symbol is an idea), and they can mean the same thing in different languages, rather like the signs in airports or the numeral 5. Just to confuse things, some of those airport signs are also called pictograms, because they are pictures of what they represent.

Then again, Egyptian hieroglyphs are a mixture of alphabetic characters and ideograms, with a few extra symbols to clarify the meaning. Few writing systems were designed from scratch: they just grew, a bit like English spelling!

The Sumerians lived in what is now southern Iraq. Ignoring the myth quoted above, their writing probably started with marks on clay that Sumerian accountants used around 3300 or 3200 BCE to record numbers of livestock and stores of grain, the sorts of records societies need, once they start farming. Over about 500 years, the symbols became more abstract, allowing ideas to be written down as well.

Egyptian hieroglyphs (literally, the word means ‘priestly writing’) are unlike Sumerian cuneiform. They probably developed separately, but maybe the Egyptians got the basic idea of marks to represent language from other people. The Harappan script from the Indus valley in what is now Pakistan and western India, seems to be another independent growth, though nobody has learned to read it yet. The civilisation which established it collapsed in about 1900 BCE, so the script did not develop further.

The oldest alphabets that we know about seem to have emerged in Egypt around 1800 BCE. They were developed by people speaking a Semitic language, and the writing only covered consonants. These variants later gave rise to several other systems: a Proto-Canaanite alphabet at around 1400 BCE and a South Arabian alphabet, some 200 years later. There were others, but we will stay with those examples.

The Phoenicians adopted the Proto-Canaanite alphabet which later became both Aramaic and Greek, then through Greek, inspired other alphabets used in Anatolia and Italy, and so gave us the Latin alphabet, which became our modern alphabet. Aramaic may have inspired some Indian scripts, and certainly became the Hebrew and Arabic scripts. Greek and Latin inspired Norse runes and also the Gothic and Cyrillic alphabets.

The Rosetta Stone solved a lot of puzzles.

Now the way was open for poetry, literature, history, philosophy, mathematics, recipes, technical information, tax, weather and astronomical records, religious teachings and more to be written down and passed from one generation to another, without the need for story-teller, whose main role was to memorise everything.

Just occasionally, we can get lucky, but most ancient systems are only ‘cracked’ by intensive work. Carved in 196 BCE, the Rosetta stone was found in 1799 by French soldiers fighting in the Napoleonic Wars in Egypt. The inscriptions all said the same thing, but in Greek, in Egyptian demotic script, and in hieroglyphics. In other words, for the first time, the mysterious hieroglyphics could be compared with a translation.

The content is fairly boring, a list of taxes repealed by Ptolemy V, but the use of three languages made the stone very exciting. When the French were defeated, it was handed over to the British, and placed on display at the British Museum in 1802.

The Rosetta Stone was described by its original French finders as ‘une pierre de granite noir’, a stone of black granite, but this was not a geologist’s granite. This term ‘black granite’, conferred in less geologically rigorous times, was applied 200 years ago by Egyptologists to a dark, fine-grained stone from Aswan. The British have always called the stone basalt, since they gained possession of it during the Napoleonic wars. Neither description is correct.

Recent cleaning and a careful examination has shown that the stone was probably sourced from Ptolemaic quarries to the south of Aswan. Probably nobody cared much what the stone was, as the important question was the text, not the material it was inscribed on.

From a geological viewpoint, though, it is neither a basalt nor a granite, but a fine-grained granodiorite, perhaps modified by metamorphic and/or metasomatic processes. For most purposes, we can think of it as a granodiorite, but in chemical terms, say the researchers who have looked at it, the stone is more like tonalite.

Granodiorite has quartz and plagioclase, but it also contains biotite and hornblende, and it is typically darker than granite. All the same, it is hard to see how it could be mistaken for basalt, but the secret to the issue lies in the reference to recent cleaning.

The confusion arose because the stone has been covered for many years with black carnauba wax, remnants of printer’s ink, used to obtain contact-prints of the inscriptions, finger grease and dirt, with white paint in the incised lettering to make it stand out.

When the stone was being cleaned in 1998, it became apparent that the stone was not basalt at all. Work based on petrographic examination and analysis of a fragment from the Rosetta Stone showed conclusively that it is a granodiorite. To be precise, the Rosetta Stone is made of a granodiorite that has probably been exposed to some extra heating. It is not basalt, but it should not be taken for granite, either.

The First Koel

Canowie Brook, Budawang Ranges.

I have been busy, putting the final touches on (working title) Survivor Kids, a book scheduled to hit the shelves in February 2020. It's about how to survive in the wilds, places like the above, how not to get lost, stuff like that. I put the finishing touches on it last night, and now I will slowly and carefully start to polish it. And now, I have more time to muse, until the edits of Australian Backyard Earth Scientist begin coming back.

Sherlock Holmes would not have approved of the dog next door.  It started barking into the pre-dawn gloom, just a few nights ago.  When looking into the case known as The Hound of the Baskervilles, Mr Holmes was more interested in dogs that did not bark — as am I, come to think of it!

I had a good idea of what had provoked the dog to action, but I had to wait until last night to confirm it, when, from a deep slumber, I heard a shriek behind our house.

It was a frightful cry, very hard to describe.  The nearest I can get would be to suggest that it sounds rather like an elderly naked duchess being goosed with ice-cold tongs.  But if it is hard to describe, the meaning of the noise is crystal clear.  The koels have arrived.

In England, they write to The Times, overjoyed to report the first cuckoo of spring.  We Sydneysiders write to the Herald, rather more underjoyed about the first koel, even though it, too, is a cuckoo.  The name (it rhymes with Noel, as in ‘The First Noel’), reflects the sound of its call, described in one of my reference books as ‘koo-well’.  This description fails to convey the full flavour and savour of the bird's cry, and so I prefer the goosed duchess.  Of course, that might just be because I never did have much time for duchesses . . .

The koels fly south around the equinox or a few weeks later, coming down from Papua-New Guinea, the large lizard-shaped island that lies above the right-hand side of Australia on your maps.  Having arrived, they choose territories where they can exploit the local feathered baby-sitting facilities, just like their cuckoo relatives in other parts of the world.  Then in the wee small hours of our early spring mornings, around 3.30 or 4 am, they start their calling. This year, they seem to have arrived later than usual.

We really should not blame the koels, for they are simply staking a claim to a territory, although the resource they care most about is nesting sites for their target species.  They are too late this year, for  the noisy miners have already hatched their first brood for the year, but there will be a second sitting, a second chance, later in the year, when high summer arrives.  In a few weeks, the koels will realise that they need to play a waiting game for a while, and they will quieten down.  Maybe.  In the meantime, we will suffer fitful snoozing from false dawn to sunrise for a few weeks.

In Australian English, there are many different meanings of ‘clock’.  It can be variously a time-piece, an embroidered design on a sock, or a twelve-month prison sentence.  ‘To clock’ can be to give a punch or a blow, or it can mean to time (a horse or a runner), or it can have other lesser meanings as well.

Our koels may be Antipodean cuckoos, but nobody in their right mind would wish to make a koel clock that would bellow each quarter-hour so unmelodiously.  On the other hand, right now, most of us Antipodeans would relish the prospect of being able to clock the koels.  Hard.

A second bouquet of scammers

This is a second excerpt from (and promo for) my recent Kindle e-book, Not Your Usual Clever Ideas  (https://www.amazon.com.au/dp/B072BCKBVQ) . For the other one, scroll down a bit, or click here: http://oldblockwriter.blogspot.com.au/2017/10/a-bouquet-of-scammers.html

The real hey-day of adulteration came with the industrial era, with large towns and better transport to carry the toxic concoctions away. Crooks in a small village were too likely to be caught in the act, or tracked down when there crimes came to light. In a large city, the sellers of adulterated foods could always blame their suppliers if the need arose. Then again, a larger world trade and new discoveries made many more adulterants possible.

In the 19th century, “cider” claimed to be prepared from concentrated apple juice, might well turn out to be sugar, fruit essence and aniline dye, with no trace of apple juice. Sweet potatoes, chicory and rye might find their way into coffee—the rye was detected when a South Brooklyn family showed symptoms of ergotism, caused by a fungus that attacks rye.

Used tea leaves might be dressed with gum and treated with iron sulfate for green tea, or black-lead for black tea, or with any mix of ferric ferrocyanide, lime sulphate, turmeric, the leaves of beech, elm, chestnut, plane, oak, willow, poplar, hawthorn, sumach, holly and sloe. There were no doubt others that were never identified.

Chocolate might be expanded by the addition of flour, starch, sugar, cocoa-nut oil, lard, tallow, sweet ochre and chalk. Sugar might contain gamboge (a resinous pigment), starch, flour, pipeclay, plaster of Paris, chalk, and even copper carbonate, lead, and mercury bisulfate.

In the middle of the 19th century, Scientific American offered a copper diammine test for detecting copper in pickles, and a test for lead in beer that involved adding sodium sulfate and looking for a precipitate of lead sulfate, while beer was to be boiled down, burning it and treating the ash with ammonia to being out the tell-tale copper diammine blue.

In London, brewers were accused of adding strychnine to beer to add a bitter taste, which they denied. Tobacco's devotees were equally at risk. Snuff might contain red lead or lead chromate, though tobacco, it seems, was poisonous enough. Either that, or the ingenuity of the crooks wasn't up to the challenge.

There was also a test to identify counterfeit guano, the 19th century's wonder additive for boosting farm production. Soon the crooks were busy, diluting the valuable Peruvian guano, but the scientists were hot on their tail, explaining how a bushel of guano weighs about 70 pounds, but if clay, marl or sand is added, it will weigh more. Then there was another test: when Peruvian guano was burned, it should lose 55 to 60% of its weight, and its ash should be white, dissolving readily without effervescence in dilute muriatic acid, leaving an insoluble residue of around 2%.

One invention caught my eye in a Scientific American paragraph from December 1855. It said that a miner at Mount Alexander (a goldfield near Bendigo) named Thomas Golightly had a process to cast quartz. The products, he claimed, were as good as chinaware. It added that he had come upon this while trying to extract gold by melting the quartz. The journal added that they had no later information on it.

I hate an unclosed story, and queried the Australian Historical Newspapers database, and found a flurry of Thomas Golightly stories and advertisements in 1854-5. The first owner of that name was a “medical galvanist” who seems to have practised his calling, treating rheumatism in Sydney, while training up two other galvanists in the Sydney area, after which he announced that he would practice in Maitland, north of Sydney. He announced that he would lecture there on galvanism, but after that, there is no trace of Thomas Golightly, medical galvanist.

Six months later, another of the same name, clearly somebody with a bit of an interest in science, appears, announces a discovery, and then disappears again. There is a mystery here: did he have to flee, and if so, was it from the law, creditors or a wronged wife? I suppose I will never know, but my greatest regret is that we cannot drink from Golightly cups and dine from Golightly plates, all produced from that easily-obtained material, quartz.

Another easily-obtained material in the appallingly unhygienic 19th century was rat skins. Even as they improved their hygiene, the Victorians made more homes for rats, and in 1850, Scientific American declared that rats were bring hunted in the sewers of Paris for their skins. But what would people use them for? 

A few years later, a gentleman in Liskeard, Cornwall, somebody with both time and ingenuity made himself a suit, entirely out of 670 rat skins, collected over three and a half years. It included hat, neckerchief, coat, waistcoat, trousers, tippet, gaiters and shoes. There was probably a limited demand for that sort of apparel, and the rat skins would need to be disguised.

While it wasn't mentioned in the article, the heading made it clear that the skins, obtained after their owners were lured by mutton tallow and killed, were destined to become gloves. The purchaser was named as John Warton, a rich leather dresser from London, who planned to buy them all. In short, the reader would understand, these would become kid gloves.

In 1864, the journal described the making of kid gloves, mentioning that egg yolk was used to make the leather supple, and stating bluntly that rat skins were not used. Given that the article failed to mention the important role played in dressing the leather by “pure” (white, dry dog droppings), the article may have been a bit of Victorian spin, perhaps.

Practical people knew back then that everything could be used to make something, though self-important British lordlings, promenading superciliously around the Australian goldfields used to be puzzled at the cry that went up: “Who killed the donkey?”. The common herd knew in their hearts that the only stuff that could be used to make a white top hat was the hide of an ass. Who could deny this delightful piece of folklore, given the match the hat then made with its wearer?

A German author looked at the plant world and declared that of 278 families, there were just 18 species for which no practical use was known. There were 740 plants used in building and another 48 could be used to roof them. Then there were the 615 known to produce poisons, 50 that gave a sort of coffee, 129 yielded a tea and 250 provided weaving fibres. There were 1350 assorted edible fruits, berries, and seeds, 460 vegetables and salads, 31 yielding sugar, rubbery substances came from more than 100, 44 could be used to make paper.

Soap could be made from 47 plants, 140 were a source of tannin, 330 yielded greases and oils, 389 provided resins and gums, 650 produced dyes while “vinous drinks” could be obtained from 200. And that was without counting 103 cereals, 37 onions, 32 arrowroots and 40 species of palm.

He might have failed to mention seaweeds, but the inventors knew about it. Thomas Ghislin (or Ghisling) patented (US Patent 40619) a material that was referred to as a “plastic compound capable of being moulded, embossed and stamped into various articles useful in the ornamental arts, like gutta percha, as it becomes very hard and durable when cold.” The ingredients include members of the Laminaria (kelps), caustic lime, sulfuric acid, India rubber, naphtha, coal-tar, sulfur, resin and alum.

Others were making artificial whalebone for horn, to be used as the ribs of umbrellas, but one clever Briton, unnamed by Scientific American, took out a patent in 1848 for an alpaca umbrella, which would cost more, but be waterproof, look better and resist fading. Perhaps the maker could have joined forces with Mr. A. B. Balcon, who exhibited a clever umbrella lock in Boston in 1847. This did not prevent theft of the locked umbrella, but it did stop an unauthorised appropriator using it.

Sadly, no picture of either of these has come down to us, leaving me with the image of a portly gentleman, trudging through wet streets, bearing aloft an alpaca on a stick.

Some inventors preferred to go for old materials, even rock. Somewhere around 1855, Honoré Baudre completed the first version of his silex piano, also called a flint piano or a lithophone. This used a set of carefully about 40 selected flints that delivered musical notes, set up rather like a xylophone, but on an iron frame. The set included two pieces of schist, which seemed to be the only rock capable of delivering two of the tones in his scale.

He played the instrument in Paris for some twenty years, mainly for the amusement of friends, but he toured his device to London at the end of 1875, when The Times said there but 28 stones which delivered a “some very sweet sounds” as M. Baudre struck them with two other pieces of flint.

Every kind of waste material was valued in the 19th century, and for the most part, the people were far from squeamish about matters relating to bodily functions. This did not extend far enough to encourage Francis Peters and George Clem of Cincinnati to explain the rationale behind their US Patent 90298 of 1869, which was for a privy seat made of four rollers in a square, able to be sat on but designed to make it impossible for anybody to stand on it.

You have to wonder about their manners in those days! Four years earlier, in 1865, German chemist Justus von Liebig went to London to oversee the application of London sewerage to agriculture. His verdict was discouraging, reported Scientific American in July:

Baron Liebig is engaged, through the corporation of London, in a controversy upon the question whether grass will grow upon sea-sand if nutriment be supplied in solution. The corporation proposes to grow Italian rye-grass on-the English sands by impregnating the sand with London sewage -in solution; but Baron Liebig tells the-Lord Mayor that the scheme is not feasible.
— Scientific American 1 July 1865, 3

People worried about the huge waste of nutrients that were running through their sewers and out to sea. Some suggested the earth closet, as a way to preserve the minerals that people were starting to realise crops needed, but nobody took any notice. In 1916, chemist Sir William Tilden wrote that “…practically the whole of the nitrogen from the food of the human population is irrecoverably wasted”.

— Sir William Tilden, Chemical Discovery and Invention in the Twentieth Century, London, 1916, p. 395.) 

In France, scientists had been exploring ways of artificially ageing wine. One favoured method involved covering bottles in horse dung in a cellar and heating it, but the researchers discovered that gentle heating in an oven, with bottles partially filled, before topping them up and re-corking was best. The horse dung could be left to fertilise the vineyards,

Sometimes though, there would be things that we just could not use. In the 1950s, Egon Larsen, science writer and my boyhood hero for his eternal optimism, the man who wanted to gamma-sterilise the washing, was optimistic about the wastes of nuclear plants:

Solid wastes can be disposed of by incineration, closed storage, open burial, or drainage out to sea. Incineration is especially valuable for treating animal carcases and as a means to reduce the volume of the solid waste, but it gives rise to active gases and ash. The discharge of the gases should be clear of windows. Burial may be used on permanently enclosed sites at levels depending on the rainfall so that local groundwater is not contaminated. Even highly radio-active solid wastes can be disposed of safely in the sea provided all relevant factors are kept in mind: movement of the surface water, the breeding and migratory habits of fish, and the possible hazard to seaweed where it is harvested for food, fertilization, or industrial use.
— Egon Larsen, Atomic Energy, Pan Books, 1958, p. 136.

Well, that was probably better than letting people take it into their sheds and playing with it!

Climbing Mount Exmouth

This went to air on the ABC on Sunday 29 October 2006 8:45AM, and you can still listen to it through this link, if you wish. One reason for placing this here is that Jeff McGill has just been in touch with me to correct a couple of points. I have sought and gained his permission to add his comments as a guest blog: you can find it here.

I keep a standard CV ready for the times when po-faced people ask me for an account of my experience, skills and habits. Among other thing, it says, more or less truthfully, that my hobbies include walking up small mountains slowly and sitting on top of small mountains wondering how to get down. Last September, I re-defined my sense of 'small', but I never planned it that way.

Another hobby is having temporary obsessions, cascades of curiosity that end up as talks like this, or books. This time, my obsession was with explorers in Australia and the methods they used. It will probably end up as a book, but it's had me off chasing all sorts of oddities. I rode camels in Central Australia a couple of years back, in part to work out how John Horrocks came to be shot by his camel.

This time my target was a mountain in the central west of New South Wales, a peak that John Oxley spotted from 130 kilometres away in 1818. By world standards, we have sad mountains in Australia. Our highest peak is barely 2200 metres above sea level, and most ranges are much less.

The Warrumbungles are volcanic remnants in central New South Wales, the result of our tectonic plate having passed over a hotspot some millions of years ago. Mount Exmouth reaches 1206 metres, making it the highest peak in the Warrumbungles. There used to be a road part of the way up, but that's long since closed, so I walked all the way from a car park at about 330 metres, but I thought I had started out much higher up. I'd looked at an old map and when I was thinking about walking up Mount Exmouth, I assumed the top of the old road was my starting place. This was not a good idea.

I'd looked at the contours and worked out the vertical part of the climb, going from the top of the old road about 750 metres above sea level. When I found the road wasn't there any more, I forgot to look at the map again, and missed noticing that I was starting much lower down. I headed off, expecting to walk up a small mountain and sit on it, but I was much more than 450 metres below the summit.

The first part is suitable even for old-age pensioners (indeed I met two British OAPs as I was walking out), and while it rises a bit, maybe 30 metres from end to end, it isn't extreme. Then you come to the old road, and that suddenly becomes steep pinch after steep pinch. It's pleasant enough if you can make your own pace, and because it bends, it's deceptive. You go up a rise, turn, and find another rise, or on one occasion, two kangaroos hurtling down the track. In one straight line it would be heartbreaking; here, it offers constant variety.

I always wear Volley sandshoes when I walk. This upset our English guide in the Troodos mountains of Cyprus recently; she wanted me to wear boots, until I showed her the soles and explained that roofing contractors here wear nothing else. Her eyes flickered at this curious Australian custom, then another Australian in our group clarified, 'On their feet', he said.

This kangaroo saw me coming and stood his ground.

Anyhow, Volleys are traditional with wilderness walkers of a certain vintage. I am of that vintage, and I've walked in them for 35 years or more. They let you feel the ground, so I walk quietly, especially when I am alone. My silent progress meant I was frequently alarmed by kangaroos feeding by the track. Animals that saw me only at the last minute and fled, thumpingly through the bush. My heart thumped even louder, but I knew they'd been equally alarmed.

Something like 250 metres to go!

Two-hundred-and-fifty metres below the peak, you come close to the mountain proper, and from a small saddle, you start walking up. That was the point where I looked more closely at the map and wondered why I was feeling so worn.

I realised my error, that the total climb was more like 850 metres, not 450. I'd now climbed 600 metres, not 200 metres, but having gone that far, I thought I would try a bit more. My legs were querulous but I spoke sternly to them. We would do the last 250 metres, I snarled.

The final climb begins as a narrow trace across and up a scree of loose rock. There was nothing too daunting, but the track drives steeply up to a bend and then doubles back on itself. Off the scree, there's a flat bit through trees, before the path slides up the mountainside again.

At one point I needed to work around a rock face carefully, with strands of fencing wire strung between two trees behind me. It was slippery, nothing dangerous, but I'd seen no fresh footprints on the way up (and I was in fact the only person up that far that day), so I knew help would be a while coming.

I'd posted a walk plan, giving 8.pm as the alarm time to send out searchers, which now seemed a bit late. So I needed to go extra carefully over stuff I wouldn't think twice about down at sea level. There was a steep drop below me, so I just took my time, leaning in and keeping three limbs attached at all times. Serious climbers might sneer at my Nervous Nellie technique, but I felt safer.

That eagle only came close when I wasn't ready.

A wedge-tailed eagle had been circling the peak all morning, and now it swooped in repeatedly, about five metres over my head as I worked around the face. Of course, as soon as I rounded the corner and got my camera out, the rotten magnificent bird lost interest in me and drifted away out of range.

So I just kept plodding up the track, wondering if I really needed all this. Suddenly, I was on top. Well, I was on the ridge, and that meant I only had little jump-ups along the ridge to the peak. My knees groaned a bit, but in the end, they jumped.

It was a perfect day for being on top of a mountain; two days later, I drove past, coming back from the west, and the peak was all wrapped in cloud. But that day I had a perfect monarch-of-all-I-survey view of the Warrumbungles. I ate salami, cheese and dried apples, I drank water, I mooched.

On top of the world.

I went there to see what Oxley saw. I wanted to see Mount Harris (which I'll get to in a moment), but it was hidden in haze. I wanted to see the mountains to the east, which drew Oxley on, through Tamworth and Walcha, down to Port Macquarie, and I saw them, but only as distant smudges.

That teasing eagle stayed well up, but kept flying so its shadow passed over me - it had to be deliberate - and because it was in the sun, I was unable to capture it with the camera. It circled at a distance until a second eagle came into view. They flew wingtip to wingtip, then the new bird rolled over and grasped at the first eagle with its talons, after which the two of them dropped, talons together, falling down the sky before they parted, recovered, and did it again. I wondered at this: was it a mating display or aggression? As far as I could see, they never made actual contact with their feet.

My knees continued to remind me that they're elderly. They'd had enough, they averred. Four hours from starting, I headed back down, each step carefully placed. The day wasn't hot, but I still used most of the four litres of water I took. I never used my kiwi jacket, my sweater, the extra food, the torch or the other emergency stuff, but they were insurance. Best of all, I didn't use the bivvy bag, an orange plastic sack large enough to put broken people in to keep them warm, dry and visible. I've carried it for 19 years, and never needed it yet.

It took three hours of slow and careful treading to get back to the car. I swore occasionally at Mr Oxley, who said that he got up there in two brisk hours, and seems to describe the route I was on. Like most of the so-called explorers, he was probably following what some of them called 'a native road', in other words, a foot track worn by generations of Aboriginal feet.

It was a hard climb.

The day after Mount Exmouth, I drove west, and then north, to walk up Mount Harris, described by a later explorer, Charles Sturt, as 'a hill 120 feet high', but one of just two rises near the Macquarie River. Mount Harris is private property, but the owner, John Egan, gave me permission to walk up it.

John Oxley visited that hill in 1818, saw the Warrumbungles, the Arbuthnot Range, as he called it, and decided to go there. He saw the Great Dividing Range from Mount Exmouth, and decided to push on to Walcha and then to the coast at Port Macquarie. Mount Harris is north of Warren and far enough west for the flies to be bad already. It was of course, the only day that my trusty fly veil wasn't in my pack.

Photography in dense fly swarms is no fun, as anybody who's been in the high country in summer will know. In spite of the flies, in spite of no veil, I came back with 500 pictures. It was spring, and there'd been rain in the west. Not a lot, but enough to make flies and wildflowers flourish.

The area's dead flat, right across the flood plain, so I was amused at one point to find a flood depth indicator in the middle of nowhere. It would be most useful in a flood to have a sign telling you that you'd been driving in two metres of water for the past five or ten kilometres.

It's the sort of country where explorers climb trees or each other's backs in desperation, seeking the sight of a landmark, any landmark, on the horizon. There are no 35-metre trees, so a hillock reaching that locally amazing height is a boon, especially when a person on top can see an interesting peak, almost 130 kilometres away.

Explorers like distant landmarks to take sights on as they travel, because it helps them map their way. One of my beefs with the school curriculum is that trigonometry would be a lot more interesting if the applications of triangulation were given better coverage in maths classes, and it'd be nice if the reliance of explorers on 'native roads' became an element in the history class.

Anyhow, there I was on Mount Harris, which I hadn't seen from Mount Exmouth because it was lost in the haze, but now I could see the Warrumbungles and Mount Exmouth from Mount Harris. They were faint, but they were there. Mr Oxley managed to see each from the other, so he must have been lucky.

Mount Harris was named for John Harris, the surgeon who patched up Governor Phillip after he was speared near my home in Manly. He also gave his name to Harris Street, Ultimo, the Sydney home of the ABC, to Harris Park in Sydney and to at least one other mountain.

In 1801, Harris went on the first expedition to study the resources of the Hunter River, and a hillock there was labelled 'Mount Harris' as well. It was used as a reference point while they were mapping the river, but this mere pimple has since fallen off the map, so I went looking for it.

There's another hill on the Hunter, originally named Mount Ann, and then dubbed Comerford's Hill, and if you go there as I did, it has a road up it called 'Mount Harris Drive', but it's not the original Mount Harris of 1801, so I was glad to have found the surgeon's second and rather more important personal mountain out west. I'm glad I toddled up Oxley's Mount Harris.

And looking back, I'm equally glad I went up Mount Exmouth, but I probably wouldn't do it again on my own, and possibly not even in company; one has to learn one's limitations with age. Or maybe one should ignore the limitations and go out in style? Not just yet though, there are too many Mount Harris-sized small mountains to walk up and sit on top of. I just need to clarify my internal concept of 'small mountain' a bit. Small is beautiful, but the genuinely small can be a joy forever.

Now make sure you read the preceding item in this blog.