He was tasked with “rectifying the Tables of the motions of the Heavens, and the places of the fixed stars, so as to find out the so much desired Longitude of places for Perfecting the Art of Navigation.” But the crown did not provide enough money to buy necessary tools and Flamsteed spent the father’s estate and the rich friend’s money to equip the observatory. Flamsteed spent 15 years making careful observations. He outlined the findings of twenty thousand observations in his work Historia Coelestis Britannica. Its third part, Catalogus Britannicus, contains 3,000 star positions. In the catalog, stars were specifically numbered. Flamsteed’s enumeration is still used today.