  From Halley's anonymous review of the first edition of the Principia forward, there has been a marked tendency to overstate what the Principia achieved, glossing over the many loose ends it left for others to recognize and address. A consequence of this is an equal tendency to distort the context of the enormous advances made in both mechanics and orbital astronomy during the eighteenth century, diminishing the difficulties those following Newton faced and their accomplishments in resolving them. The Principia is peculiar in this regard, for a list of its achievements without mentioning their loose ends overstates what it accomplished, but a list of its loose ends risks understating its extraordinary achievements. In an effort to strike a balance we here list eleven major scientific issues of the time to which Book 3 supplied answers in the sequence listed, the answers, and the most important loose ends in the reasoning offered in the evidential arguments for those answers.