on the fly-leaf of a copy of the 'Petty Tracts' published by Boulter Grierson (1769) at Dublin, which contains the principal works of Sir William Petty, and is the edition referred to throughout the notes in the present book, in the quotations from his writings.
By the kind permission of Mr. Charles Monck, I have been allowed to reproduce the picture of Sir William Petty, by Sir Peter Lely, now at Coley Park; and by the kind permission of the Master and Fellows of Magdalene College, Cambridge, I have been able to present the readers of this book with an authentic likeness of the celebrated 'double bottom' vessel, from the Pepysian Library at that College.
I desire to acknowledge specially the valuable help I have received in regard to several points in the seventh chapter from Professor Henry Sidgwick.
The map illustrating the settlement of Ireland was originally prepared for Mr. Charles Walpole's 'History of Ireland,' and is reproduced by the kind permission of Messrs. Kegan Paul, Trench, Trübner, & Co.
1894.
