The depth and variety of Hariot’s intellectual and scientific resources, his honesty of purpose, his fidelity of character, his eminent scholarship, his unswerving integrity, and his command of tongue, rendered him alike invulnerable to politicians and to royal minions.  He was with Raleigh at Winchester and in the Tower, off and on, as required, from 1604 to 1618, except during the last voyage to Guiana.  He was at the same time a pensioner, a companion, and confidential factotum of his old friend the Earl of Northumberland both in the Tower and at Sion for fifteen years.  Watched as these two prisoners were, ensnared, entrapped, and entangled for new evidence against them, it was necessary for Hariot to pursue a delicate and cautious course, to eschew politics, statecraft and treason, and to devote himself to pure science (almost the only pure commodity that was then a safeguard) metaphysics, natural philosophy, mathematics, history, and literature.  He was their jackal, their book of reference, their guide, their teacher, and their friend.

Raleigh found himself in December 1603, lodged in the Tower, innocent, as is now generally admitted, of the charges against him, but legally attainted of high treason.  All his worldly effects therefore escheated to the Crown.  The King out of pure cowardice (for he dared not carry out the sentence of the Court) waived the horrid parts of the sentence-too horrid even to be quoted here-and commuted it to execution by the block.  He also waived the immediate forfeitureof property acquired under Elizabeth’s reign, and even allowed Raleigh to complete the entail of certain estates to his wife and son.

The Governor of the Tower and his Lieutenant were at first officially kind and friendly, extending many privileges to win his confidence.  If there had been any treason in Sir Walter they would most certainly have wormed it out of him, for his eyes at first were not fully open.  He still believed in the honour and fidelity of his mock friends at Court.

When no more satisfactory evidence of his guilt could be smuggled out of him, or his companions, in support of the unjust verdict, they began, in 1605, to abridge his privileges and darken his lights.  At first his friends and visitors were cut down to a fixed number.  There is a list among the Burleigh papers in the British Museum by which it appears that Lady Raleigh, her maid, and her son might visit Sir Walter.  For this they took a house on Tower Hill near the old fortress, where they lived six years, or as long as this privilege lasted.

Then Sir Walter was to be allowed two men servants and a boy, who were to remain within the Tower.  Besides these he was permitted to see on occasion, Mr Hawthorne, a clergyman ; Dr Turner, his physician } Mr Johns, his surgeon ; Mr Sherbery, his solicitor ; his bailiff at Sherburne ; and his old friend, Thomas Hariot, with no official designation.