Tycho Brahe (1546-1601) was a Danish noble man and an astronomer. One of the advantages is that he was an aristocrat and could buy a copy of Ptolemy's Almagest , and some sets of astronomical tables, which showed the positions of the planets at any given time. His accurate observations were based on a large wooden quadrant, part of a circle with a nineteen foot radius, that took twenty men to set up. His very large staff and several sets of equipment permitted four independent measurements of the same thing simultaneously