He published a two volume work Histoire de lastronomie ancienne in 1817 then Histoire de lastronomie du moyen age in 1819 two volumes of Histoire de lastronomie modern in 1821 and his work on the history of astronomy in the eighteenth century was published by Claude Mathieu after Delambres death GrattanGuinness in notes that he approached the subject matter more as a calculating astronomer than as a historian

Could you correct the punctuation please?
He published a two volume work Histoire de l'astronomie ancienne in 1817, then Histoire de l'astronomie du moyen age in 1819, two volumes of Histoire de l'astronomie modern in 1821, and his work on the history of astronomy in the eighteenth century was published by Claude Mathieu after Delambre's death. Grattan-Guinness in notes that he approached the subject matter more as a calculating astronomer than as a historian.