Of Beaufort and Bortle …

Sir Francis Beaufort (1774-1875) a British Naval Commander, later Admiral, devised a scale by which to record wind strength. It was initially for use at sea based on observational characteristic. It ranged from 0 -Calm to 12-Hurricane and, for example at force 3-Gentle Breeze wave crests begin to break. It was adapted for use on land correlated with other observational criteria. I can remember some representative wind strengths from my scouting days :-

  • 3 Gentle Breeze – Girl Guide’s skirt begins to rustle.
  • 6 Strong Breeze – glimpse of under wear
  • 8 Gale – skirt over Girl Guide’s head
  • 10 Whole Gale – Girl Guide stripped naked
  • 12 Hurricane – retrieve Girl Guides from treetops later

In 2001 John E. Bortle came up with an observational scale to record light pollution in the night sky. Bortle 1 is a dark sky with no light pollution, Bortle 9 is an inner city sky where only the moon, planets and a few bright stars are visible. It is based on observations that anyone can make such as whether you can see M15, M4, M5, and M22 with the naked-eye which would be a Bortle 3 – Rural Sky. ( I personally have never seen these but I believe there may be an overpass just north of London where you can see all of them from one vantage point).

Most humans live in cities and unless you live in North Korea the nearest dark sky is quite a drive away. I live in a Bortle 2 area but being in other ways a typical human I hankered for something more. My trip to the desert was made while the moon was but a waning crescent in order to bask in the glow of a Bortle 1. And of course there was only a short break in the clouds on the first night.

The second night found me in the Little Desert contemplating Grass Trees (Xanthorrhoea sp.) and looking for M22 where M stands for Messier

also known as NGC 6656, is an elliptical globular cluster of stars in the constellation Sagittarius, near the Galactic bulge region. It is one of the brightest globulars that is visible in the night sky. The brightest stars are 11th magnitude, with hundreds of stars bright enough to resolve with an 8″ telescope. M22 is located just south of the Ecliptic, and northwest of Lambda Sagittarii (Kaus Borealis), the northernmost star of the “Teapot” asterism (Wikipedia)

It may be in the photos. If you find it please let me know.

 

 

Wail …

The Wimmera River rises on the inland slopes of the Pyranees Ranges near Ararat, western Victoria. It heads in the general direction of the Murray but it doesn’t make it that far. It flows through the towns of Horsham and Dimboola and usually discharges into Lake Hindmarsh. When times are particularly dry Lake Hindmarsh dries up. When times are particularly wet it may overflow and begin to fill a series of usually dry lakes on the fringes of the Big Desert. It is the longest land-locked river in Victoria.

Along the way the river forms the eastern boundary of the Little Desert National Park. It is one of my favourite places. Whether it should be called a desert is a moot point. It is certainly sandy and in places there are well formed dunes, the region is quite arid. On the other hand vegetation cover is pretty good for the most part. The further west you go the more convincing the argument¬† for a desert becomes especially if you bog the wheels in deep sand on a hot summer’s day.

The river margins are quite different. Black soil covers the sand and some quite tall trees, River Red Gums mainly, attract the birds and other creatures. The trouble with national parks though is the prohibition of one of my dearest companions. Wail State Forest is on the eastern bank of the Wimmera River. You can camp on the bank and look into the park. Two hundred metres back from the water you can bog your wheels in deep sand, the same birds fly back and forth and you can take your dog.

I was there last night.

Varanus varius

I was setting up camp around midday when this big lizard decided that he’d be happier up a tree. The day before had been cold (by local standards, everything’s relative). It was a little sluggish. Usually they are quick to get well away from people, this guy was happy to sit in the sun for a while.

I surprised a second one later on and was able to get some closer shots in better light …

The claws are impressive, so too is the tongue …

Monitor Lizards are found in Africa, Asia and Australasia. There are about 50 species in all. The largest of them is the Komodo Dragon Varanus komodoensis in Indonesia. It gets to more than 3 metres in length. Australia has 27 described species but Victoria has only two monitor lizards, the Lace Monitor and Gould’s Goanna. A big Lace Monitor grows to a little over 2 metres whilst Gould’s can only manage about 1.6 metres. The dark and light bands under the lower jaw are diagnostic of the Lace Monitor, V. varius.

They eat birds eggs, nestlings and any other small animal they can catch. They lay their eggs in termite mounds, mum comes back to break the youngsters out when they hatch.