The letter accompanied a copy of Newton's 'Principia'. It explains the nature of the work, and especially the theory of tides. It begins 'May it please, &c. I could not have presumed ...', and concludes 'I doubt not but if your Majestie shall please to suffer me to be admitted to the honour of your presence I may be able to give such an account thereof as may be to your Majesties full content. I am, &c., Edmond Halley'.