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Sunday, 28 June 2015

Making a humidity jar

This is another thing that was in Australian Backyard Naturalist, but now I am providing more detail on how to make one. While I was writing that book, I kept the slug, seen here on the left, in a humidity jar for about ten months. I used to take it out from time to change its food and clean the jar out, but it lived there quite happily.

The first thing to say is that few animals do well when they are kept sopping wet. This includes frogs, which go into water to mate or as an escape from land predators, but which are not really aquatic. Tadpoles are, but not grown-up frogs, which can drown

At the same time, few animals do well on completely dry land. This frog on the right must have come close: I found it in Morocco, on the edge of the Sahara Desert (there was a body of icky water nearby for them to breed in). This frog was also odd, in that it crawled, rather than hopping, but frogs are also found in Australia's deserts.

The thing is, all animals have ways of avoiding drying out. They may shelter under rocks, or in leaf litter for example, but when you keep them captive, you may limit their flexibility. So to keep them moist but not wet, the trick is to keep them in a humidity jar.

Raw plaster, which you can buy in packets at the hardware store as "Plaster of Paris" can absorb water and a layer of plaster at the bottom can help keep a jar from drying out. Here is what you need to set this up:
Check list: a spatula, dry powdered plaster, a clean screw-top jar (I prefer 400 gram Vegemite jars), some water, and something to catch any spilled plaster.

On that last item, I generally use coloured cardboard as a backdrop for photography, and here, it serves a double purpose.

Add some water to the clean jar.  The amount is not all that important, but I suggest 1.5 to 2 cm. Some people suggest drilling a few holes in the plaster, but I have never bothered doing this.

Then add some plaster to the jar. Notice the spillage in the picture on the left?  It always happens, so it's a good idea to sweep it up before it goes on the floor. Use a dustpan or a vacuum cleaner and never use a damp cloth!! (If you do, you will make matters worse. Trust me.

You want a layer of plaster 8 to 12 mm deep, and there needs to be water on top of the plaster. Don't worry about that, because the plaster will still set under water.  I always bang the jar on the bench a few times to get any air bubbles out, and to get the plaster surface level.

Put the jar to one side with the lid on (just in case it gets tipped over. Click on the picture on the left for a larger view that will show you the excess water.

After 20 to 30 minutes, take the lid off, pour out the remaining water, wipe the inside of the jar with damp paper, and your humidity jar is ready to put some animals into it.

If you want to keep tiny web-making spiders, choose a suitable twig a and poke its thick end into the plaster while it is still wet.

The sky's the limit: even leeches can live there...but then what do you feed them on?

You can see one solution to leech feeding, on the left ...

Not recommended!

In case you are wondering, it was involuntary feeding, but my wife is a biologist and called me for a photo opportunity before we removed it.

General note that I am adding to some of my blog entries: I have lots of different interests. If some area interests you, look at the very end and you will see a set of tags called labels. These are hot links that will give you a list of other articles with the same tag/label.

Saturday, 20 June 2015


Carmine is neither an opera nor a gangster. Carmine is a red colouring matter, now derived from the cochineal beetle, often said to have been first prepared by a Franciscan monk at Pisa and manufacture began in 1650. In fact, the name comes from qirmiz, the Arabic and Persian name for Coccus ilicis, a relative of the cochineal beetle, which gives us kermes, the name of the evergreen oak, Quercus coccifera (merely Latin for 'Coccus-bearing oak') on which these beetles were found. The genus name for the beetles, by the way, is just the Latin word for 'scarlet'.

The alternative name for the red dye, or for the scarlet grain insect is alkermes, is recorded by the OED from as early as 1610, beating out the unnamed Franciscan by a goodly amount. We get the present word from the Latin carminus, which was unrelated to carmen, a song (as in Carl Orff's Carmina Burana) but along the way, the colour gave rise to quite a bit of martial music, after it was used to colour the British army's uniforms.

Cochineal, depending on its treatment, can yield anything from scarlet to crimson to orange. This dye comes from the Mexican "cochineal beetle", Coccus cacti, which lives on a cactus, one of the prickly pears, which raises an interesting Australian angle: when prickly pear was introduced into Australia, legend has it that it was brought in so people could make jam, or so they could make hedges from the plant.
When you look at the discussions of the Sydney Acclimatization Society in the 1860s, it is clear that cochineal production was considered a good idea and a desirable aim.

In fact, the beetle is no coleopteran at all, but a hemipteran, part of an order that includes cicadas, leafhoppers and aphids, now called Dactylopius coccus. Another species of Dactylopius, along with its cactus host, were brought to Australia in the first English fleet, but both the cactus and the insects died.

The plan for an Australian cochineal industry was inspired by the knowledge that, in the late 1600s, a sometime pirate and explorer, William Dampier, captured some cochineal on a Spanish ship with great glee, knowing that it was worth its weight in gold. The find would have been of little value, though, if a Dutch scientist in London in the early 1600s had not accidentally (they say) dropped some solution of pewter into a preparation of cochineal.
Drebbel's submarine, Wikimedia

This led the scientist, Cornelis Drebbel, better known for his invention of a human-powered submarine, to discover the way of mordanting cochineal with tin salts — pewter, after all, is mostly tin. In mordanting, the dye is made to "bite in" to the yarn, so that it is not easily dislodged in later washing, not like the indigo that dyes your denim jeans, which is preferred over newer, 'faster' dyes, because it fades. Once Drebbel found his process, the cochineal dye clung fast to the cloth, and the new red was a bright and distinctive colour.

Cromwell's death mask, Wikimedia
That brightness was a key issue in 1645, when Oliver Cromwell founded his New Model Army, the first national military force commanded by professional officers. Cromwell wanted to give his soldiers a sense of identity, and dressed them in red coats dyed with Drebbel's new cochineal dyeing process. And that was how Britain got the troops, still known best to Americans as "the redcoats".

Now here we can see why Australians in the 1860s might have thought it a good idea to grow prickly pear for cochineal beetles. They were, after all, part of the British Empire, on which the sun never set.

Just as 'carmine' comes from the middle east, so does our word 'scarlet'. It is an aphetic or shortened form of the Old French escarlate, supposedly from the Persian saqalat, a kind of rich cloth.

There is also a fish called a char, which is usually red, but this has less to do with glowing coals, and more to do with the Gaelic ceara, red, or cear, blood. A char is also a cart or wagon, a relative of the chariot, which becomes, when fitted with seats that face forward, a char-à-banc or charabanc, but these seem to have nothing to do with charcoal, either.

For some reasons, the worst sins were scarlet, and Judas Iscariot is often portrayed as a redhead, yet cardinals wear hats of a colour called cardinal red. And then there was Hilaire Belloc, who hoped his epitaph would read "his sins were scarlet, but his books were read".

General note that I am adding to some of my blog entries: I have lots of different interests. If some area interests you, look at the very end and you will see a set of tags called labels. These are hot links that will give you a list of other articles with the same tag/label.

Tuesday, 16 June 2015

This table is not for turning

Part of a table of logarithms.
In the mid-1200s, Alfonso X, Alfonso the Wise of Castile, caused a set of astronomical tables that we now call the Alfonsine Tables, to be published in Toledo, which is why they were sometimes also called 'Toledan tables'. In 1620, a Swiss watchmaker, Joost Bürgi, published his Arithmetische und geometrische Progress-Tabulen, a set of logarithmic tables, and in 1627, Johann Kepler published a set of logarithms in the Tabulae Rudolphinae, which commemorated his patron Rudolph II, Emperor of Austria, and King of Bohemia.

Those examples aside, most tables in Europe up until that time, and even for quite a long while after it, were tables that you could eat at, or turn on an opponent when you played a game at them, or you could drink people under them, but these were all tables with legs, and unless those sitting at them were bent on a bit of graffiti work with their daggers, there would be precious little recorded on them.

Times tables.
Yet at some point, the flat slab sort of table became, at least for mathematicians, first and foremost a collection of figures, displayed in a regular grid. We came to have contents tables, mathematical tables, data tables and tabulation, and even the tab key on our computers, which had been used in setting up tables on the typewriters that gave us our computer keyboard. This then, is an exploration of tables and how they came to have their modern meanings. 

In the Middle Ages and before, the table was more than just a place to eat: it was a place of great social occasion. Chaucer tells us that the squire in the Canterbury Tales was a fine young man: 

Curteis he was, lowely, and servysable,
And carf biforn his fader at the table.

Here, Chaucer reflects on the way that a table you sat at for eating, and where you sat at it in the Middle Ages, was also a sign of rank, a bit of a league table, you might say. The fact that the squire sat at the same table as his father, the knight of the Tales, and carved for him, defines him as holding high rank. This follows a comment about the knight himself, earlier in the General Prologue:

Ful often tyme he had the bord bigonne
Aboven alle nacions in Pruce

In other words, the knight sat at the head of the table, or board, in Prussia, where knights of many nations gathered to help the Teutonic Knights war against their heathen neighbours in Lithuania. So in Chaucer's time, there was no real distinction between a board and a table, but there was a distinction about where you sat at the table. This distinction is still preserved today in places where honoured guests are seated at the High Table, while other common folk are allocated positions below the salt.

In the Summoner's Tale, we hear of a friar who would beg for food:

A peyre of tables al of yvory,
And a poyntel polysshed fetisly,
And wroot the names alwey, as he stood,
Of alle folk that yaf him any good.

But once he was out of their sight,

He planed away the names everichon
That he biforn had written in his tables

While these tables that the friar used were associated with food in a way, they were small enough to carry around. In fact, they were wax-coated ivory tablets, on which he scribed with a carefully pointed stylus (the poyntel), but then as soon as he was out of sight, with a quick wipe, he flattened the surface, ready to start a new sucker list on what the Romans would have called a tabula rasa, a clean table.

The Romans were rather keen on using tables to display things, and these were often slabs of marble, on which important things were carved. Their Twelve Tables enshrined the basis of Roman law, and when Cicero was a boy, he was required to learn these by heart. Moses is usually depicted as coming off Mount Sinai with the Ten Commandments on two tablets of stone.

So this type of table was often a tablet, more like the 'table book' that Nathaniel uses in Love's Labours Lost than any item of furniture (or medication). We still call a notepad a 'writing tablet' today, occasionally, but a table is more commonly a flat slab with legs, used for sitting at, or perhaps it is used for a governing council of some sort, though we still speak always of a board of directors, even if they sit at a 'board table'. Documents drawn to the attention of those present are tabled, meaning they are placed on an item of furniture.

Shakespeare uses both 'board' and 'table', in roughly equal proportions to indicate an eating place, but he refers in his sonnets and elsewhere to the tables of the heart, apparently meaning something like loving memory, something that could be written on like a writing tablet, but this leaves open the question of how we came to have other sorts of tables.

The original table was a flat slab or board, that might be thrown across trestles to make the furniture sort of table, but they could also be used to inscribe rules, laws and commandments, and both these meanings apply to the Old English tabule, but the mathematical use appears to come from astronomy. In the Franklin's Tale, Chaucer writes of Aurelius bringing forth his "tables Tolletanes", his Toledan astronomical tables, and Chaucer notes that they were "ful wel corrected", so the tables were written on something correctable.

Could it be that astrologers and such carried these tables around on slabs, or maybe even on wax-coated ivory tablets like those of the Summoner? This was before the start of printing, and so it is at least possible. After all, astronomers, long after that time, recorded their results on planks of timber, which were sometimes, in some contexts, referred to as tables, at least in a figurative sense. In 1390, John Gower wrote "He broghte him sauf upon a table, Which to the lond him hath upbore", describing somebody coming ashore from a shipwreck, clinging to a plank.

The other piece of evidence for this speculation that a plank was used in place of paper comes from Urbain Leverrier, the French astronomer, and his encounter in 1859 with an amateur called Lescarbault. This man, who turned out just to be a poor observer who was mistaken, had apparently detected a planet near the sun, the hypothetical planet Vulcan, and Leverrier was keen to get Lescarbault's data, and define the orbit of the planet, but to do that, he needed enough data to calculate the orbit, and that meant getting all of the observations of black dots that Lescarbault had recorded.

This was at a time when paper was still quite expensive, and sadly for Leverrier, the man's figures were all kept on a board, for lack of paper, and he planed all the old figures off when he had no further use for them. By then, 'tables of contents' were common, so perhaps we got the new use from something like the 'times table' that might be displayed on a board in a school room, though Charles Babbage published a Table of Logarithms in 1827.

There was also an 1826 paper that Babbage read to the Royal Society about an engine "for the purpose of calculating tables and impressing the results on plates of copper" — perhaps those copper plates were tables? The term certainly dates back as far as 1805, so far as life expectancies were concerned, because in that year, Joseph Banks urged the famous Captain Bligh to become Governor of New South Wales, observing in passing that Bligh's life was not yet over: 'I apprehend that you are about 55 years old — if so you have by the tables an expectation of 15 years' life'.

It probably matters little, for all those tables, logarithm, trigonometric and even probability, have all been replaced by a calculator, just as surely as the 'log tables' once replaced Napier's bones. If we did not still have the periodic table and timetables to explain, we could probably let the matter rest. Then again, maybe those are exactly the sort of tables that can be displayed on a board.

Tuesday, 9 June 2015

Making a fly and insect trap

Last week, I was working at and on the periphery of the Bellingen Readers' and Writers' Festival, where I gave workshops to children in Years 3 to 6, a selection from my novel about mad sheep, did a panel appearance and also gave the Mary White Address at the Dorrigo Rain Forest Centre.

Three things stood out in the schools program.  One was making a pooter: see the Youtube clip here; the use of an upside-down umbrella, which I will come to later, and the construction of a simple trap for flies that can be adapted to catch fish or small crustaceans.

This is a simple idea, based on a simple hack that took me ages to develop, but which I am sharing for free. This is a very simple device to make, once you know a very simple hack that is easy to apply, but it was very hard to come up with. Like all simple hacks, there are probably lots of other ways that readers can apply this. If you think of one, please share it with me by way of a comment on this blog.
The finished product in its dry-land form.

You need two 1.25 litre clear plastic bottles, some sharp straight scissors, a sharp knife, and preferably a pair of nail scissors. You also need a thick wad of old newspaper to stop you stabbing the table or desk, and you need your thinking cap on! If you can’t think, wear a thick gardening glove to protect your other hand, the one that isn’t operating scissors,

Look at the pictures as you follow the instructions.

Take one of the bottles, and cut a slit, just below the bottle’s “shoulder”. Then use the straight scissors to cut around the bottle to make a funnel. If this part has a cap on it, remove the cap, but keep it.

Now take the other bottle. Remove any label on it, and use the knife or scissors to make a small hole in the side.

This is the point where you need to think, so you don’t cut or stab yourself. Then use scissors to make a neat round hole, about the same size as the neck of the funnel.

Go slowly, remembering the rule of holes: you can easily make a hole larger, but you can’t ever make a hole smaller. Don’t worry if the hole is smaller than the neck: here comes the trick!

Using the picture for reference, make a series of small snips, about 5 mm long, radiating away from the centre of the circle.

Now you have a hole, surrounded by a series of flexible flaps. Push the funnel through, and it will clip into place.

You may need to try this a couple of times before you get it right. Then if there isn’t a cap on the bottle, fit one.

Using the trap

If you remove the funnel, you can add some bait, and what you use is up to you: a bit of banana peel or an apple core will attract fruit fly, fresh or rotten meat ought to attract bush flies, house flies and blow flies. What you use is for you to decide. Just remember that the easy way to get bait inside is to remove the funnel and use that hole.

You can also use the trap in water: add a few pebbles to weigh it down, tie a string to the neck of the bottle, add some bait, tie the string to something, and sink the trap in water for 24 hours or so before pulling it in, using the string.

You might also like testing to see if a waterproofed torch works at attracting stuff overnight: this is a tool that doesn’t come with instructions, so play with it as you wish — and remember that the trick with the flaps around the hole probably has other uses. If you think of one, please tell me!

Sunday, 7 June 2015

The usefulness of white ants

You must consider a termitary as a single animal, whose organs have not yet been fused together as in a human being. Some of the termites form the mouth and digestive system; others take the place of weapons of defence like claws or horns; others form the generative organs.
— Eugène Marais (1871 - 1936), The Soul of the White Ant, 1937.

Not all social animals are social with the same degree of commitment.
— Lewis Thomas (1913 - 1993), The Lives of a Cell, Penguin Books, 1978.
Termites and a nest
Angophora costata, near Sydney
Termites, white ants, are evil and destructive, no use at all, right? Well, not quite. Ecologists see termites filling the same role in our bush that the big herbivores of the African plains occupy. They clean up hard-to-digest wood, converting it to soluble stuff with the assistance of assorted microbes, amazing things, but termites have other uses. 

Macrozamia plants.
I have an environmental education address to give in Dorrigo in June, and that got me thinking about the poor quality land in the Myall Lakes National Park on the east coast of Australia.

(Note added on posting: the address has now been given, and  a  version of it will appear here at some future time.)

The Macrozamia plants in the forest are more often found associated with the Smooth-barked Apple or Rusty Gum (I wonder why it’s called that?), Angophora costata, than with the more common Blackbutt, Eucalyptus pilularis.

The reason for this is at once both complex and delightfully simple.

As you can see from the pictures above, Angophoras are usually gnarled, with holes or hollows where branches have broken off, and termites live in these trees, where they hollow out the insides. 
You can see the hollows after storms.
Macrozamia seeds, with a 37 mm coin.
Brushtail possums live in the hollows made by the termites. The possums eat the orange outside of Macrozamia seeds, and drop the partly eaten seeds around the base of their home trees.

The seeds germinate where they fall, which explains the distribution of Macrozamia plants. The roots of the Macrozamia 'fix' nitrogen, and so improve the sandy soil the trees grow in. The trees then grow better, providing more heartwood for the termites, who make more hollows for the possums. Everything is connected!

The old settlers had another use for termite mounds:
In the course of this and the following day’s journey we passed many of the gigantic ant-hills common in some parts of New South Wales. They are great conical heaps of finely worked earth cemented into a hard mass, and from six to ten feet high, with no visible orifice outside, nor did I see a single ant about them, though I closely examined several. I have been told they are the work of a white ant, and, from their magnitude, should suppose them the habitation of a species of termite. When cut open, they display numerous small cells, but on our journey I had neither the time nor inclination to destroy and investigate their domestic arrangements myself. The earth of which these ant-hills are formed, is so finely prepared by the little architects that it is used by the settlers in the neighbourhood as plaster, and frequently as cement for floors.
   — Louise Ann Meredith (Mrs Charles Meredith), Notes and Sketches of New South Wales.  London: John Murray, 1844, and Ringwood: Penguin Books, 1973, pages 68-69.
Please be nice to termites!
(Some of the pictures used here: the Angophora stump, the Macrozamia plants and seeds were taken after this was written, just north of The Entrance on similar dunes near Lake Macquarie. It's the same set of associations, I think. The possum is from Brisbane City Council via Wikimedia Commons.)

General note that I am adding to some of my blog entries: I have lots of different interests. If some area interests you, look at the very end and you will see a set of tags called labels. These are hot links that will give you a list of other articles with the same tag/label.