Greaves had entrusted his will to his friend and fellow-traveller in the Levant, the Arabic scholar Edward Pococke. The will had originally stipulated that Greaves' collection of astronomical instruments (astrolabes, quadrants, telescopes etc.) was to be left to Oxford university. But by 1649 Greaves (who was staying at Sir John Marsham's house in Rochester, Kent) had become increasingly exasperated with the academic situation at Oxford since the civil war. He wrote to Pococke asking to him to send the will to blot out his gift of his instruments to the university (which had cost him more than a hundred pounds), because he "so far despaired of any future encouragement to learning and ingenuity in Oxford." Greaves repeated his request a few months later, asking Pococke to open the will and strike the words out himself. Pococke seems to have eventually complied with Greaves' wishes, since after Greaves' death in 1652 his executor and brother Nicholas Greaves kept hold of his late brother's collection.