Kate C

DISPLAYING POSTS BY: Kate C (180)

Kate C

Kate is MV's online writer and editor. Her job is to dig up great stuff to put on the museum's website. Kate loves shiny things, cake and creepy crawlies.

Catalogue of cephalopods completed

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by Kate C
Publish date
4 June 2014
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Everyone loves a happy ending. And everyone loves octopuses. The recent completion of the third and final volume in the revised FAO Catalogue of Cephalopods of the World nails it on both fronts. 

Cephalopods of the World Volume 3 Cover of the new FAO Cephalopods of the World Volume 3.
Image: Emanuela D’Antoni
Source: Food and Agriculture Organization of the United Nations
 

This is a brilliant – and free – resource designed to assist people working in fisheries to identify the cephalopods that we humans are most aware of, namely the ones we've identified, that we eat, or can cause us harm. Volume 3: Octopods and Vampire Squids was co-authored by MV's Dr Mark Norman and Dr Julian Finn. They are also are two of the four series editors.

'Octopus’ berrima Spot the 'Octopus’ berrima in the sandy substrate! (The inverted commas signify that this species is provisionally placed in the genus Octopus.)
Image: Julian Finn
Source: Museum Victoria
 

Years of work and drawing from cephalopod researchers worldwide sees FAO Catalogue of Cephalopods of the World summarising descriptions of species for practical use by non-specialists. "We've distilled it down to diagnostic characters that will allow people on research or fishing vessels to identify species," says Julian. "It's a review of all the taxonomic work that's out there, for people who don't have immediate access to the literature." The species descriptions focus on traits that are easily measured, which is no mean feat for animals famous for changing their shape and form at will. Says Julian, "everything is based on characters that survive preservation and are consistent across members of a species, such as numbers of suckers, presence or absence of structures, and relative lengths of body components."

Julian and Mark also note that this project would not have been possible without significant financial and moral support from the Australian Biological Resources Study and the Hermon Slade Foundation. This allowed them to do the work on octopus taxonomy that was required for this new edition of the Catalogue. 

Argonauta argo The beautiful female Argonaut, or Argonauta argo.
Image: Julian Finn
Source: Museum Victoria
 

So, if you have an interest in, as Ze Frank calls them, 'the floppy floppy spiders of the sea', head to FAO and download a free copy of FAO Catalogue of Cephalopods of the World Volume 3 (PDF, 25.77Mb). And in case you need a reminder about why you love octopuses, here's a video showing how they can open jars from the inside (while we humans sometimes struggle to open them from the outside).

 

Hair of the dog

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by Kate C
Publish date
8 May 2014
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The Aztecs were dog people. They were in awe of the jaguar for its stealth and fighting prowess, but for domestic companionship, they chose dogs, not cats.

And their dogs didn't look much like your typical house mutts. Known in English as the Mexican hairless dog, the Nahuatl-speaking Aztecs called their breed the Xoloitzcuintli (pronounced show-loh-its-queen-tli) after Xolotl, a god with the head of a dog who helped the dead in their passage to the underworld. (Xolotl was also the beleaguered twin of Quetzacoatl and ultimately turned himself into the amphibious axolotl, but that's another story.)

Mexican hairless dog A Mexican hairless dog called Izzy Frittata.
Image: Xugardust
Source: Xugardust via Compfight cc
 

The Aztecs exhibition at Melbourne Museum features a dog statue carved from stone in about 1500. This little dog has the half-closed eyes and raised head of a dog receiving a hearty scratch under the chin. It seems an affectionate portrait of a much-loved friend. However, when the Aztec owner of a Xoloitzcuintli died, their dog was sacrificed to accompany them on the journey ahead. This sounds horrifying to dog lovers today but the Aztecs also raised dogs for food and had no qualms about putting them to death.

Sculpture of a dog Sculpture of a dog about 1500. When a person died, if they had a dog it was sacrificed after the funeral. The dog would then guide its owner’s soul through the nine levels of the underworld.
Image: Michel Zabe
Source: © Instituto Nacional de Antropologia e Historia (INAH)
 

Almost unknown in Australia, Xoloitzcuintlisor Xolosremain quite rare in Mexico and the USA because they nearly vanished completely after the arrival of the Spanish in Central America. Believing them to have healing properties, people in remote Mexican villages sheltered these sacred dogs and protected them from mixing with other mutts. Accordingly, they survive as one of the oldest breeds, and have been used by geneticists to examine the history of dog domestication. Frida Kahlo kept Xolos and included them in her paintings, helping to boost the popularity of the dogs and save them from another near-extinction in the 20th century.

Museo Dolores Olmedo Pick the real dog! Three Xoloitzcuintli dogs lazing about a statue of this sacred breed in the garden of Museo Dolores Olmedo, Mexico.
Image: Joshua Bousel
Source: joshbousel used under CC BY-NC-SA 2.0
 

Of course, the most striking feature of the Xoloitzcuintli is its virtual hairlessness, which is caused by a dominant gene. The gene is lethal when inherited twice (homozygous) – a puppy with two copies will not be born alive – while Xolos without a copy of the gene have an ordinary furry coat. Xolos often have missing teeth, probably linked to the same hairlessness gene.

Xoloitzcuintli puppies A pile of Xoloitzcuintli puppies
Image: Xugardust
Source: Xugardust used under CC BY-NC-SA 2.0
 

Links and references:

Vilà C, Maldonado JE, Wayne RK (1999) Phylogenetic relationships, evolution, and genetic diversity of the domestic dog. Journal of Heredity Jan-Feb;90(1):71-7. (PDF, 184 kB)

Cordy-Collins, Alana (1994) An unshaggy dog story. Natural History Vol. 103 Issue 2, p34

Hairless dogs compete at Reliant Show, Houston Chronicle, July 20 2012 

Cork Colosseum x-ray

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by Kate C
Publish date
17 April 2014
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An x-ray machine usually employed for mammography examined an unconventional patient earlier this year: a model of the Colosseum made from cork around 1800. Thanks to generous assistance from Lake Imaging in North Melbourne, object conservator Sarah Babister now has a view inside one of our most curious objects.

Four people discuss photograph Conservators Sarah and Dani show radiographers Jeff and Ghazia a photo of the Colosseum model.
Source: Museum Victoria

cork Colosseum model The facade of the Colosseum model. (HT 24386)
Source: Museum Victoria
 

Radiographer Ghazia adjusted the settings of the mammography machine to accomodate this unusual material—cork is much less dense than human tissue—and produced wonderfully clear and informative images of several pieces of the Colosseum.

Woman with x-ray machine Ghazia placing a piece of the Colosseum on the mammography machine.
Source: Museum Victoria

Woman with computer Ghazia adjusting the levels of the x-ray to best show the hidden structure within the cork Colosseum.
Source: Museum Victoria
 

We think that our Colosseum was built by English model-maker Richard Du Bourg (or Dubourg), but in the absence of a signature, Sarah is looking for characteristic materials and construction techniques that could confirm its maker. Further research by historian (and the museum’s Head of Humanities) Richard Gillespie and genealogist Neil Gill is fleshing out the intriguing story of Du Bourg and his models; Richard recently visited similar objects in overseas collections for comparison. Sarah and Richard will present a talk about the model and its story next month as a part of the History, Cultures and Collections seminar series.

From 1775 to 1819, Du Bourg’s models of classical ruins were the height of fashion and his a well-known London exhibition. “He’s a fascinating character,” says Sarah. Notoriously, his working model of Vesuvius destroyed an entire exhibition when its eruption set fire to all the other models on display. “He lived until he was in his early 90s and even though he’d been very famous he was living in poverty.”

Sarah explains that cork models “were really popular at a certain time and were kept as tools to teach students. Then they fell out of fashion and a lot of them were disposed of.” This may explain Du Bourg’s impoverished old age, and is the reason why the museum has this model at all – in 1929 it was sent from the Science Museum in London to the Industrial and Technological Museum in Melbourne.

cork Colosseum detail Sarah holding a large piece of the Colosseum model.
Source: Museum Victoria
 

The model is over a metre wide and in poor condition. The base it sits on is cracked and the gesso applied to the perimeter is flaking, and several sections of wall have broken off. These broken sections are a mixed blessing, since without them there could be no x-rays, which reveal the lead pencil marking lines, and pins and nails used to hold the pieces of cork together. This information may help confirm whether Du Bourg made the model, but will also help Sarah reattach the broken pieces.

X-ray image of a piece of the cork Colosseum X-ray image of a piece of the cork Colosseum. The metal pins, and decorative carvings covered in lead paint, appear white.
Image: Lake Imaging
Source: Museum Victoria
 

“Most of the pieces are there so the model would be virtually complete with the exception of a few small columns which might need to be replicated,” she says. “I’d love to put it back together so it can be viewed how it should be viewed because it’s such an amazing object. The level of detail in the carving is wonderful, and cork lends itself so well to representing that ruinous state.”

To learn what the x-rays revealed, come along to Richard and Sarah's free seminar on 14 May, titled For the Nobility, Gentry & Curious in General: Richard Du Bourg’s Classical Exhibition, 1775-1819.

Links:

Cork Colosseum model on Collections Online

Rehydrating specimens

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by Kate C
Publish date
25 March 2014
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Recent workshops brought together natural sciences collection managers and conservators from far and wide to learn techniques for preserving wet specimens – those preserved in fluids like ethanol and formalin.

Fluid preservation workshops Fluid preservation workshops underway at Melbourne Museum's conservation lab.
Source: Museum Victoria
 

The workshops, hosted at Melbourne Museum, were supported by the Australian Institute for Conservation of Cultural Material (AICCM) and taught by UK natural history conservator Simon Moore. Dani Measday, MV's Natural Sciences Conservator, says "you can’t learn easily natural sciences conservation in Australia, so people are really jumping on the chance to build skills in that area." With participants from Canberra, Sydney, Brisbane and even New Zealand, it was also a rare opportunity to meet others working in the field. “Museum people love to talk shop," says Dani, who toured the visitors around MV's collection stores. "There was definitely a lot of discussion about what people were doing in their museums. It's great to build up a network of people you can call on when you get stuck.”

Over four days, the workshops addressed some of the major problems of wet collections, one of which is dehydration as the preserving fluid evaporates. “The ones that were really dehydrated tended to come out of jars with rubber gaskets in the lids, which can perish quite quickly," says Dani. "Or they can get twisted and end up with a really poor seal.” A highlight of the workshop was seeing dehydrated specimens returned to full size under Simon's guidance.

Workshop participants cleaning Workshop participants cleaning perished rubber gaskets from mammal specimens.
Source: Museum Victoria
 

During the workshop, Dani worked on a juvenile koala specimen affectionately nicknamed Drinky Bill. This koala was originally collected from French Island and came to the museum in 1957 via the Healesville Sanctuary. In the intervening years, poor Bill lost all of his alcohol and was a dry fist-sized husk rattling around an empty jar.

The process of rehydration, explains Dani, begins with placing the specimen in warm water with a surfactant. "It's basically a detergent to break down surface tension to help water penetrate into the specimen." The cells expand as they take in water, and the specimen returns to its original shape and weight over several hours.

 

Next, the specimen is re-fixed in formalin to stop the decay. Then it's back to ethanol in a series of baths of increasing strengths. "You need to move it through several different concentrations of ethanol gradually. If you go straight from water, it's a big change in pressure for the specimen." Dani's koala spent a few hours in each of 10, 30 and 60 per cent before the end point of 70 per cent. To remove any air bubbles and to make sure the koala was submerged, Dani used a vacuum chamber conveniently housed next door in the preparation department. "The preparators use it to remove bubbles when they’re casting in resin."

Koala specimen before (left) and after (right) rehydration treatment. Koala specimen before (left) and after (right) rehydration treatment.
Source: Museum Victoria
 

The resulting transformation is amazing. At the workshop's conclusion, some specimens in very poor condition were returned to near original state. Restoring the animal's natural size is particularly useful, as skins and skeletons can't tell us this information. It leads to some truly amazing applications; Senior Curator of Mammals Kevin Rowe says a researcher recently contacted him to find out the dimensions of a bandicoot. "He was designing radio tracking vests for bandicoots which don’t have necks suitable for collars. The best way to figure out the dimensions of a bandicoot is to look at a fluid specimen." This is because wet specimens "preserve internal soft tissue better than skins and skeletons. They also preserve the anatomical features of sperm, stomach contents, parasites–essentially everything in and on a specimen." 

Taxidermy conservation workshop

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by Kate C
Publish date
18 March 2014
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It’s clear that the old penguin specimen needs a lot of work. Age or accident has detached the bird’s head from its body, and preparator Steven Sparrey is carefully working PVA glue into the break in the neck. This will consolidate the edge and provide a sound surface for reattachment. Eventually, preened feathers will conceal the join and the penguin will be whole again.

Damaged taxidermied penguin Detail of damaged taxidermied penguin specimen.
Source: Museum Victoria
 

We’re at a workshop for people in the business of preserving natural history specimens – collection managers, preparators and conservators – led by visiting UK expert Simon Moore. The museum’s conservation laboratory is busy with people transforming elderly and damaged collection objects into exhibition-ready specimens, using specialist techniques that are very rarely taught in this country.

Taxidermy workshop Taxidermy conservation workshop in the conservation lab at Melbourne Museum.
Source: Museum Victoria
 

Sometimes the damage occurs from wear and tear, especially where specimens have done time in the museum’s interpretive collection. Other times it’s inadequate preparation at time of taxidermy – overstuffed specimens tend to split as the skin shrinks with age. Simon explains, “many of the specimens are decades old, and materials just become more brittle with time. “A small bump when handling can have drastic results on a fragile specimen, and the head is often the first to go.
We turn back to Steven’s penguin. “The skin on birds in particular is very thin and vulnerable to tearing,” says Simon. “In this case, the neck was overstuffed. As the skin dries out and retracts back onto the underlying material, it starts to split.” 

The penguin also needs a wing reattached, so Steven drills a fine hole for a galvanised steel rod to hold the wing on a natural angle. Next to him, Michael Pennell is finishing work on a mounted Regent Bowerbird, freshly reunited with its tail and perch. “He’s a little bit cleaner than he was this morning and I’ve filled a few little holes and splits.”

Man and bird specimen Preparator Michael Pennell working on a Regent Bowerbird mount.
Source: Museum Victoria
 

Elsewhere in the room, people are creating supporting armature for rabbit ears, cleaning feathers and mending tears in batwings with Japanese tissue. This tissue, says conservator Dani Measday, has unusually long fibres and resists tearing. “It means that it’s really strong and you can do all kinds of things with it. We use it to repair paper and books , but you can use it as fill, to strengthen and replicate fibres , or as a consolidating surface. What we’re doing with it here is making replacement skin. With adhesive, it has a tightness and tautness just like skin.”

repair to bat specimen Careful repairs to a bat specimen using Japanese tissue.
Source: Museum Victoria
 

Karen Roberts and Brendon Taylor are restoring tiny bat specimens. It's painstaking work; they have pinned out the fragile wing membranes and patched the holes with Japanese tissue. The purpose of the specimen dictates the treatment from here. “A scientific collection item can have warts and all, with minimal intervention,” says Simon. “Here we could put a gentle lacquer to hide the tissue, but obviously for display you’ve got to colour them in.” The extent of treatment for exhibition work can be deceptive, as the conservation treatments aim to draw the eye away from repairs so the specimen can be read as a whole.

Two men with penguin specimen L-R: Preparator Dean Smith with Simon Moore, looking at a damaged King Penguin mount.
Source: Museum Victoria
 

Simon’s own knowledge comes from decades of experimentation and consulting with natural history collections around the globe. “I’ve learned lots myself throughout the years and I’m trying to advance the technology, giving credit where it’s due. There aren’t many people doing taxidermy conservation and they keep trade secrets.” The techniques that Simon shares in workshops like this will help keep scientific and display specimens in good nick for study, research and exhibitions in years to come.

Great Melbourne Telescope volunteers

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by Kate C
Publish date
13 March 2014
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Each Wednesday, a dozen or so engineering and astronomy buffs head to a museum workshop to restore one of Marvellous Melbourne's grandest marvels. The Great Melbourne Telescope (GMT), scorched by the Mount Stromlo fires in 2003, is being resurrected thanks to an estimated 10,000 hours of volunteer work (so far). This group recently received a Certificate of Appreciation in the 2013 Arts Portfolio Leadership Awards.

GMT restoration team Mathew Churchward reading out the Arts Portfolio Award commendation to the Wednesday restoration workshop team.
Source: Museum Victoria
 

The workdays have "a bit of a men's shed feel about them," says Senior Curator Matthew Churchward. He coordinates the project alongside Curator of Engineering Matilda Vaughan. The combined knowledge in the room – all members of the Astronomical Society of Victoria, many with experience in engineering, electronics, astronomy and optics – means this piece of 19th-century technology is in expert hands.

Three men with computer L-R: Barry Cleland, John Cavedon, new volunteer Norm and Stephen Bentley working on technical drawings of GMT parts.
Source: Museum Victoria

Building telescopes is a common pastime for amateur astronomers; volunteer Barry Adcock has a home-built a 14-inch diameter telescope for his backyard dome observatory, plus another telescope that allows him to view the stars from inside his house. For many, stargazing is a habit they picked up when very young. Scottish-born Jim Pollock recalls a lunar eclipse in 1949 during which the moon was bright blue after forest fires in Canada. "In the atmosphere, tiny particles of pinene, the oil from the pine trees, scattered red light beautifully and just let the blue light through." Another volunteer, Barry Clelland, remembers looking up as a kid from his backyard in the suburbs and thinking, "that's half the universe there. You could see the Milky Way in Heidelberg back then."

On this day, a sub-group is working on the mirror polishing and grinding machine, a beautiful hulking contraption with a cast iron frame and gears and shafts. The GMT's half-ton speculum metal mirrors tarnished over time, so every few years they were removed and reconditioned with this machine. "We're still trying to work out exactly how it was driven," says Matthew. The mirror sits on a rotating table and as it moves, the polishing head also rotates, "so it doesn't get a flat spot in any part of the mirror. It keeps moving as it's rubbing." Or, like "patting your head and rubbing your tummy," jokes volunteer David Linke. The team hopes to have the polishing machine working within the next year as a hint of what's to come with the telescope itself.

David Linke with the mirror polishing machine. David Linke with the mirror polishing machine.
Source: Musuem Victoria
 

In the workshop, parts of GMT are laid out on pallets and benches. With a grin, David says, "it's a big jigsaw puzzle, isn't it?" Above it all, for equal parts reference and reverence, hangs a large-scale historical picture of the GMT in operation.

Museum workshop A view of the workshop with the GMT’s lattice tube in the foreground. On the back wall hangs the large historical photograph of the GMT at the Melbourne Observatory.
Source: Museum Victoria
 

Most of the large parts of the GMT were recovered after the 2003 Mt Stromlo fires. "Oh golly, it was a dirty job to get everything out of that cube," recounts David. "The aluminium had melted from the dome and filled up the screw holes so you couldn't see where things were undone." Many months of work saw the GMT dismantled and its surviving parts audited. Fortunately, the GMT had an unofficial champion in Barry Clark, who has been involved with the Melbourne Observatory since 1955. At that time, decommissioned equipment went into storage and was at risk of being lost. Says Matthew, "Barry's been instrumental in recovering bits and pieces that were hidden under the floor. He's discovered some key bits of equipment that went right back to the very earliest observatory at Williamstown."

Detail of the dismantled cube of the GMT. Detail of the dismantled cube of the GMT.
Source: Museum Victoria
 

Lengthy reverse-engineering is recreating the missing parts. "We go out there with a ruler and pencil and paper, take measurements and sketch it up roughly," says Campbell Johns. The measurements are made in imperial units to match Irish manufacturer Thomas Grubb's original specifications, before conversion to metric for fabrication. Some of the team with technical drawing expertise convert the workshop sketches into digital CAD files. There's a lot of cross-checking with old photographs, drawings and the extant parts.

"We don't even know if there was ever a full set of working drawings," says Matthew. "It appears they did the basic layout and started building it before they had the detailed design. You can see evidence in the way parts were modified during the construction process, like spots flattened out of a casting to make a seat for another component." A volunteer adds, "Pretty amazing given in those days there were no angle grinders or power drills or oxy welders. It was all done with cold chisels."

Three men with computers L-R: Barry Clark, Barry Adcock and Mal Poulton working on optics design specifications for the GMT.
Source: Museum Victoria

So why are these men devoting their spare time to this project? It's evident from the way they talk about the GMT that they admire its history and innovation. In addition to its astronomical achievements, including the first observations of southern nebulae, the ingenious nature of its design bewitches them. It had two axes and counterweights that allowed just one person to move the beautifully balanced telescope. In its lifetime there were larger scopes, but none so nimble. Matthew's view is that it's an opportunity of a lifetime for amateur enthusiasts to build such a large telescope; few individuals would have the resources to do so alone. Other volunteers nominate restoring an important part of Melbourne's history as their prime incentive – they want to see it back in its old home.

Indeed, the end goal is to return the working telescope to the Melbourne Observatory for public viewings. Its original configuration restored, there may be new electronic additions to allow digital photography or remote operation via the web. As Matthew says "It could be very inspiring for astronomy in Victoria."

Links:

The Great Melbourne Telescope website contains the story of the telescope, and updates about its restoration through the ASV's Phoenix newsletter

Follow the GMT project on twitter: @GMT21stC

Great Melbourne Telescope on Collections Online

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