William Dawes (1762-1836) volunteered for service with the First Fleet and was attached to the Marines on board the Sirius.
A competent astronomer, he was supplied with astronomical books and instruments at the recommendation of Astronomer Royal, Rev. Dr Nevil Maskelyne. In Sydney Cove he was employed on shore from March 1788 and built an observatory at Dawes Point. He also worked as engineer and surveyor.
He was part of Philip Gidley King's party sent to welcome the French expedition of La Perouse after their arrival in Botany Bay when he would have met Joseph Lepaute Dagelet (1751-1788?), the astronomer with the French expedition. This letter is written to Dawes from Botany Bay shortly before the departure and disappearance of La Perouse's entire expedition. Dagelet probably perished at the Vanikoro Islands in 1788. Dagelet writes of his regret at not being able to visit the site of Dawes' observatory before he leaves, and comments extensively on Dawes' plans for his observatory.