Queensland & British 1882 Transit Expedition, Jimbour

A transit of Venus takes place when Venus passes directly between the Sun and the Earth, becoming visible against the solar disk. During a transit, Venus is visible as a small black circle moving across the face of the Sun.

Transits of Venus reoccur periodically. A pair of transits takes place eight years apart in December followed by a gap of 121.5 years, before another pair occurs eight years apart in June, followed by another gap, of 105.5 years. The dates advance by about two days per 243-year cycle. 

Transits of Venus were in the past was used to provide an accurate determination of the sun's parallax (from which is deduced our distance from the sun) & assisted in solving other important astronomical questions depending on this baseline, including determining the size of the Solar System. As a result, the Transit of Venus in 1882 saw multiple simultaneous expeditions proceed to key locations around the world to view this rare astronomical event.

One location chosen by the British expedition was Jimbour, in Queensland's Darling Downs. Jimbour was chosen due to its favourable climactic conditions, as the Darling Downs skies were found to be particularly clear and suitable to astronomical observations. A member of the expedition to Jimbour, Cuthbert Edgar Peek, was struck with the purity and clearness of the colours seen through the telescope & marveled at the superiority of vision in Queensland compared to his observations taken in England. 

The headquarters of the British Expedition were at Radcliffe Observatory, Oxford, England, & it was there that the telescopes & other instruments to be used at the various stations were erected &, adjusted by expedition organiser, Edward James Stone. In order that members of the various expeditions should know beforehand what they might expect to see, a model Transit of Venus was employed. Each observer repeated the process with the model many times to ensure extreme accuracy of the observations.

The Queensland & British 1882 Transit Expedition (29 October 1882 to 18 December 1882) to Jimbour included official observers from the Royal Geographical Society, Captain William George Morris & Lieutenant Leonard Darwin (son of naturalist Charles Darwin), & self-funded amateur astronomer Cuthbert Edgar Peek, who accompanied the expedition with his assistant, Charles Grover.

The official observers were provided with two six inch equatorially mounted telescopes by Cooke of York, England, two sidereal clocks, chronometers, & an altazimuth instrument. The telescope Cuthbert Peek employed in his own observations was an achromatic telescope of six & four tenths inch aperture by Merz of Munich, mounted on an equatorial stand by Cooke of York, England, & weighed about a ton.

The party left England (Tilbury) 24 August 1882, sailing on "Liguria". They took observations on board the ship & observed the 'splendours of the southern sky'. An outbreak of smallpox in Cape Town, South Africa, prevented the team from leaving the ship, & the party arrived in Melbourne on 8 October. They then travelled to Sydney, arriving 16 October. The group stayed in Sydney for a week, then sailed to Brisbane on board "Katoomba" (a small steamer of the Australian Steam Navigation Company), arriving off Moreton Island on 26 October. 

On the morning of 2 November 1882, the party boarded a train for the journey to Jimbour. It took 6 hours for the train to reach Toowoomba, & on getting out for a short break, Charles Grover discovered that Cuthbert Peek had ridden the whole way there on the buffer beam in front of the engine, stating that he had never seen such magnificent scenery before.

The journey continued, & the party arrived at Macalister Station in the late afternoon. Morris, Darwin & Peek went on to Jimbour, & Grover was left in charge of the instruments, which would be transported to the 12 miles to Jimbour on 5 drays, each pulled by 12 horses, the next day. The heavily laden drays sunk in the soft ground of the track to Jimbour, & the going was slow. The team camped overnight, & at 1:00am on the morning of 4 November 1882, the drays & their precious cargo arrived at Jimbour. Grover states that "all the Station was aroused as there was a great commotion as the drays were drawn in to the enclosure". The weary teams were unharnessed & left to graze while the men got a few hours' sleep.

Within 2 days, four small wood & canvas huts, which had been brought from England, were erected in the paddock close to Jimbour House, which at the time was unoccupied & placed at the disposal of the expedition. James Wallace was the Manager at the time. Three of these huts contained the equatorial telescopes, & the fourth & smallest hut contained the altazimuth instrument & sidereal clocks. No time was lost in erecting & adjusting the instruments, which was completed by 6 November, & observations of the Southern skies were successfully carried out from that date. 

The arrival of the expedition at Jimbour caused a great sensation, & local people began to arrive to "see the wonders of science". As Cuthbert Peek's telescope was the first to be in working order, it became the centre of interest. Throughout the day, crowds came to see the telescope & its mechanisms, & at night Peek arranged for his observatory open for an hour or so after sunset so that visitors could have the opportunity to gaze at the wonders of the universe. The observatory of Morris & Darwin contained many precision instruments, & it was deemed unsuitable for curious visitors.

Unfortunately, heavy cloud cover on the morning of 7 December 1882 prevented the Jimbour expedition having a clear view of the Transit of Venus. All was not lost however, as important astronomical observations were carried out in the days preceding the transit. Cuthbert Peek, who spent six weeks at Jimbour at his own expense, observed double stars and star-clusters, paying special attention to the nebula round η Argus, one of the wonders of the southern sky, which he later described in his memoir.  

Although their equipment was packed up by 15 December, it was not until 20 December 1882 that Peek & Grover left Jimbour. They stayed in Brisbane until their ship departed for England on 3 January 1883.