He diversified into making telescopes and erected a public observatory near his factory at 1 Upper Charlemont Street , Portobello , Dublin .
Thomas started out in 1830 in Dublin as a metal billiard - table manufacturer .
Thomas diversified into making telescopes and erected a public observatory near Thomas ' factory at 1 Upper Charlemont Street , Portobello Dublin Dublin .
Thomas started out in 1830 in Dublin as a metal billiard - table manufacturer .