The Maclear monument

A more significant monument than it would at first seem....
In 1838 Maclear, then Astronomer Royal, carried out the first trigonometrical survey in South Africa, while he was checking on the shape of the Southern hemisphere, and marked this point (in the small circular gap in the paving) which then became the starting point for coastal surveys of the whole country, first West and then East - and later for all trig surveys in South Africa (the only country in the world to have a single, fully coordinated system.) There's a bottle buried there, with a document giving Maclear's account of this.
For me there's a serendipitous link... I retired to Aurora because we'd discovered and fallen in love with the beautiful little village. Our house happens to be just around the corner from this monument. Two years later, researching family history, I was astonished to find that my great-grandfather, whose home was far North of this at Hondeklipbaai, but who travelled widely, had been the local facilitator for Maclear. Did that buried bottle belong to my great-grandfather, I wonder? And did he enjoy its original contents...?