A preliminary letter shows the thoroughness of Froude's methods.

The date is the 5th of March, 1862.
"DEAR LADY SALISBURY,--If Lord Salisbury has not repented of his kind promise to me, I shall in a few weeks be in a condition to avail myself of it, and I write to ask you whether about the beginning of next month I may be permitted to examine the papers at Hatfield.

I am unwilling to trouble Lord Salisbury more than necessary.

I have therefore examined every other collection within my reach first, that I might know clearly what I wanted.

Obliged as I am to confine myself for the present to the first ten years of Elizabeth's reign, there will not be much which I shall have to examine there, the great bulk of Lord Burleigh's papers for that time being in the Record Office--but if I can be allowed a few days' work, I believe I can turn them to good account.