Keeping snails and slugs away

A large land snail, found on club moss
under a banyan tree on Tanna, Republic
of Vanuatu on the Pacific Ocean.

A land snail from Margaret River,
Western Australia.

Are you fed up with slugs and snails?

This is a pbi, a partly-baked idea, suitable for somebody looking for a science project.  That means you need to do most of the work!

You can get rid of snails and slugs with bare copper wire, several dry cells (torch batteries—or flashlight batteries if you are American), or a small power pack (transformer-rectifier) and to test it, you will need some live slugs or snails.

Get some advice on connecting the batteries or the power pack to the wires. Look up <electronics components site:.au> for local suppliers and enter <battery holder> to find what you need. (That works in Australia, Americans may need to vary that wording.)

Old power packs from discarded phones or other gadgets will do, if they deliver 3 volts or less.

The idea is to make an electric fence to keep snails out of a seedling bed. The best design is two parallel wires, each connected to one terminal of your power supply.


You will need to work on insulating the wires from each other and the ground. I suggest using small pieces of polystyrene foam, cut from waste packaging and pushing the wires through, so as to keep the wires apart and out of contact with the ground.


Questions worth asking:

• How many volts does it take to repel a snail?

• What voltage do you need to keep slugs out?

• If they leave slime across the wires, does this conduct electricity and "flatten" the battery, or waste electricity? 

Some ancient history:

Now here is an old version of the electric fence, based on the way two different metals will generate a small current by forming a "galvanic couple", a sort of simple battery, presented by Septimus Piesse.

It was written up in English and American science journals before the end of 1863, so it is now a very old idea, first published in Scientific American in 1863. The image below comes from that journal.

How to set out the zinc and the copper. 
Scientific American May 2. 1863, p. 276. 

Having a few pet plants which slugs and snails are particularly fond of as food, I have devised the following simple and efficacious mode of protecting them against their and my enemies; and as this plan may be useful to some of your readers, I herewith send you a description of my galvanic circle.

Procure a flat ring of zinc, large enough to encircle the plant; make a slit in the ring after the manner of a keyring, so that it can be put round the stem of the plant and then rest upon the ground.

Now twist a copper wire into a ring very nearly of the same circumference as the flat zinc ring, and putting it round the plant, let it rest upon the zinc, as in the illustration.

No slug or snail will cross that magic circle; they can drag their slimy way upon the zinc well enough, but let them but touch the copper at the same time and they will receive a galvanic shock sufficient to induce them at once to recoil from the barrier.

A bit of simple introspection and research should lead you to the conclusion that the three volts mentioned in my design was massive overkill.

Death and the Rhinestone Maidens

And now for something completely different: an instruction in opera appreciation in one act, 'twixt the Cab Sav and Cav and Pag in the Café Mozart.

Death and vengeance, that's the stuff

A statue of Hans Sachs in Nuremberg. He appears in
Die Meistersinger von Nürnberg (which is German for

The Sound of Mucus).

Demanded by the opera buff —
They don't care who does the deeds.
So long as someone sings and bleeds.

They're not content with minor strife,
They have to see some loss of life.
One more thing: the operatic
Kind of death must be dramatic:

Make it that, and they won't gripe
If cause of death is trash and tripe.
A thrown-down gun, a fallen dagger
Will do to make the player stagger,

Sing and fall down on the left
While all the cast sing they're bereft.
In Wagner's operas, deathly pallor
Pays the entry to Valhalla –

Opera deaths are rarely cool,
And most are prone to ridicule.

Casting call: young Irish hoofers who don't quite understand what
Lohengrin is all about. It isn't actually an opera about a contented

cow, at least not the Wagner one. TheTossini version was, but who
has heard ofTossini today?

In Cavalleria Rusticana,
The hero's stabbed by a green banana.

And after that, it's all downhill
There's lots of sillier ways to kill:
Pagliacci dies a death more mean,
Crushed by a falling aubergine;

And in some opera by Rossini,
The murder's done by ripe zucchini.
If you think that's a weak libretto,
You haven't yet seen Rigoletto.

So that's the story, mark my word:
In opera, death is quite absurd.
If you're a star then one thing's certain:
You'll bleed before the final curtain.

Now off we go, the opera's on
But don't ask why they're all called "Don"
We've had our meal and it was filling
So let's avoid an off-stage killing.

This is dedicated to all those people who haven't realised yet that an opera is just a musical in which the story (called a libretto after the great writer Antonio Libretto) is much more complicated.

Caution: this post may contain traces of nuts.
That said, all facts contained herein are of equal reliability.

There is a new book on the way

I got back from Vanuatu (of which more later) on Wednesday night, and on Thursday morning, a courier arrived with a box from what is now my alpha-publisher, the National Library of Australia.

It's miserably wintry here, so I donned a windproof jacket and slipped out into the watery sunshine where Chris took a series of shots, most of which featured me squinting and blinking, but we achieved this one.

For those who know me best as a children's author, this is the other side of the coin, a serious look at the naturalists and natural history artists who visited (or in one or two cases were bred and raised in) Australia.

In many ways, this is a spin-off from Australian Backyard Naturalist which came out in May and which is drawing very pleasing reviews. That is most definitely a children's book, showing younger readers how to bother and enjoy the hidden life that is all around them.  (You can see some of my other books on the National Library bookshop's site.

Illustrations of an alleged bunyip skull,
drawn from the Sydney Morning Herald
by way of Trove.

The idea, when you write for an institution like the National Library is that you seek to showcase their collections. Libraries these days are far more than musty collections of old tomes: they have digital arms, collections of maps, paintings, real objects and more, and the library's staff are excellent at helping me pick the eyes out of what they have and want to flaunt.

Another side is that I get into the Trove digitised historical newspapers, and I show readers, in passing, just what gems can be found there.  On a personal note, I was interested to discover an engagement notice for my father to a lady whose name was mentioned once or twice with gritted teeth by my mother. This was before he met my mother, but there's some history there that I never knew: so you never know what will turn up.

For example, one of my upcoming books nails down a little-known conspiracy which was undertaken to get Australia's gold rush started.  More of that later, but it's a fascinating example of PR and social manipulation in colonial Australia. (There's more about that in the post before this one.)

Anyhow, back to Curious Minds, I was searching for illustrations from the NLA collections for Australian Backyard Naturalist, and having to pass up lots of delicious stuff that I knew well, involving people I knew well.  I fired off a casual email, suggesting to Susan Hall that there was probably a book there.  Equally casually, she asked for a rough outline, and just as casually, I slapped it together, suggesting that she put it in her backburner file, her bottom drawer, for later consideration.  I was in no rush, and thought it needed twelve months of good solid research.

Back came an email saying it was "go" and could I submit in six months?  I said it needed twelve months, but I was cajoled into working twice as hard and getting 12 months' work done in six.

The outline changed a bit as I found other people who merited greater discussion and I cut one or two out because there was no real interest. They were not people with curious minds.

My business card describes me as a freelance curious mind.  This levity is a cunning filter, because the po-faced, the prim and proper, the boring people I would never wish to work with, shy away at my informality, and good riddance.  The term "curious mind" first came into print when I had to write a blurb for a book, and I recalled an exchange with an old friend where he commented on my productivity and asked how I did it.

"I have a curious mind," I told him.

"Yes, I can see that," he said—but the meaningful way he said it showed that he was playing with the words.

I needed no more than that, and so the blurb read something like "Peter Macinnis finds that his friends and his detractors all agree (with differing intonations) that he has a curious mind."

This is one illustration that didn't fit, which is a shame. Only a
Frenchman like Charles Lesueur would give the male kangaroo

  such a lascivious eye. Click on this image to see a larger version.

And now it's a book title.  And a book, which I have in my hands.  It weighs 1050 grams, it looks beautiful (that's why I like working with the NLA: they do superb design work), and now I have another task on my hands: to clean up and redesign the information page about the book. Right now, it's sloppy and messy.

I took three mss away with me, and worked through half of one of them, so now I need to make many, many changes to the Word file, I need to finish working through that ms, and I need to get onto two others. I have a radio talk to record next week, and I always tweak my scripts up to the very last moment, and I am giving a workshop for Australian Backyard Naturalist in Canberra on August 23 (scroll down in the link) and I have some more fieldwork coming up. I will, I hope, be a little more forthcoming with fun stuff for the younger reader.

That said, I owe this blog a piece on writing for younger readers, and why Martin Amis was a prat when he suggested that he would only write for children if he suffered brain damage.