1. [Letter (copy) : William Petty, 1650 December 16 to Samuel Hartlib] Creator: Petty, William, Sir, 1623-1687 Published / Created: 1650 December 16 Call Number: OSB MSS FILE 16797 Collection Title: Osborn Manuscript Files Container / Volume: Folder 16797 Image Count: 3 Resource Type: Archives or Manuscripts Found in: Beinecke Rare Book and Manuscript Library > [Letter (copy) : William Petty, 1650 December 16 to Samuel Hartlib]