It is difficult for any one who has not tried to write a work of this kind to anticipate the difficulties through which it is carried out, inasmuch as its proportions are being constantly changed according to the materials the writer receives.<br><br>My first idea was to sketch Lord Palmerston as I have sketched Mr. Canning in 'Historical Characters.' But when the large collection of Mr. Temple's letters from which I have quoted was placed in my hands, these letters were so characteristic of the writer, and so good as letters, that I thought they ought to find a place in his biography.