The mystery is now solved by giving here the letter in full. It is even
more important than Dr Zach with all his enthusiasm supposed. It is not,
however, from the pen of Northumberland, though none the less
interesting on that account. The letter is in the well-known handwriting
of Lower, of Tra'venti, on Mount Martin, near Llanfihangel, in South
Wales, to his dearly loved friend and master Hariot at Sion, and is
dated the 6th of February, 1610. The letter fills two sheets of foolscap
paper. The first sheet of four pages Dr Zach found at Petworth, and it
is to be hoped that it still exists there. The other sheet of four pages
is preserved in the British Museum (Add. 6789). How long these two
sheets have been separated it is difficult to tell, but probably from
Hariot's day, that is, for more than two centuries and a half. The two
fragments are now brought together and printed for the first time
complete, the first half from Dr Zach's text, and the latter half copied
verbatim direct from the original autograph manuscript, Brit. Mus. Add.
6789.

LETTER FROM SIR WILLIAM LOWER MATHEMATICIAN

AND ASTRONOMER TO THOMAS HARIOT AT SION

FEBRUARY 6, 1610.

I have receeved the perspective Cylinder that you promised me
and am sorrie that my man gave you not more warning, that I
might have had also the 2 or 3 more that you mentioned to
chuse for me. Hence forward he shall have order to attend you
better and to defray the charge of this and others, that he
forgot to pay the worke man. According as you wished I have