sandblasting usayizi wemidiya market kulindeleke ukuthi sikhule ngo--6.5% cagr kusuka 2016 kuya 2023. usayizi emakethe sandblasting abezindaba global, emqulwini imigomo, ukuba kukhule nje ngaphansi 6% cagr. us sandblasting usayizi abezindaba emakethe ukuba idlule usd 96 million 2023. the trigonometric beacons (trig beacons) in south africa originated from the western cape, cape town to be exact and they were based on star observations and precisely measured baselines . sir thomas maclear between 1833 and 1870 and sir david gill between 1879 and 1907 were initially tasked to verify the size and shape of the earth in the southern hemisphere and later to provide geodetic control for topographic maps and navigation charts. from these beginnings the network was extended to eventually cover the entire country and which eventually comprised about 29000 highly visible trigonometric beacons on mountains, high buildings and water towers. Kuyaqondakala kuJosephus ukuthi uJaddua washona kungekudala nje ngemuva kokushona kuka-Alexander the Great, ngaleso sikhathi uJaddua wayezoba neminyaka engama-80 ubudala futhi walandelwa yindodana yakhe u-Onias.[Ii]