mile posts offset from this chord to the arc (chord and arc are used when surveying latitude to allow for curvature of the earth). This continued until the survey intersected longitude 141º (now known as Cameron Corner), a distance of 285 miles 24.96 chains. That spot is marked by the Cameron Corner Survey Marker. Watson withdrew from the survey and Cameron then returned to the Zero Obelisk at Barringun and marked the line to the east in a similar fashion. Cameron then erected a 1 ton survey post on the west bank of the Barwon River to mark the end of the survey. Surveying the Queensland-South Australia border The survey of the Queensland – South Australian border was first carried out by South Australian surveyor, William Barron, as Queensland did not have a surveyor available at the time. Barron carried the marking of the 141st meridian up to its intersection with the 29th parallel of south latitude (Cameron Corner), and then on to Cooper Creek (90 miles north of that intersection). Barron was forced to return to Adelaide in late 1879 due to ill health. South Australian surveyors, Augustus Poeppel and assistant Lawrence Wells, took over the survey in January 1880. The line to the 26th parallel was continued, a distance of 552¼ miles from the Murray River. Here Poeppel met up with Queensland surveyor, Alexander Hutchinson Salmond. Together they took star observations for latitude using both a transit theodolite and sextant to fix the position of that parallel. They marked the corner with a willow post 12 feet long, which was sunk over an iron bar. The line was marked by mile posts mounded and trenched. A zinc plate was attached to the posts declaring the distance from the centre of the Murray River. Poeppel then continued to mark the 26th parallel to the west. He reached the 138th meridian by the end of 1880 and returned to Adelaide in March 1881 due to the prevailing drought conditions. Many hardships were encountered on this survey as the line passed through vast stony, waterless plains, salt lakes and large sand hills. It was thought to be the most inhospitable country in Australia. While Poeppel was recuperating in Adelaide, the South Australian triangulation survey had reached beyond the border. It was found that when checking the mile posts, they were in error due to the fact that Poeppel's chain was 1