This is the modernised version of Dowland's instructions on where to tie frets to the fingerboard of one's lute. Spellings, grammar and punctuation have been largely converted to Standard English, but the sentence structure has been retained. The huge chunks of text have also been broken into smaller paragraphs in order to make it easier to follow.
Wherefore take a thin flat ruler of whitish wood, and make it just as long and straight as from the inward side of the Nut to the inward side of the Bridge, then note that end which you mean to the Bridge with some small mark, and the other end with the letter A, because you may know which belongs to the one and to the other; then lay the ruler upon a Table, and take a pair of compasses and seek out the just middle of the Ruler; that note with a prick, and set the letter N. upon it, which is a Diapason [octave] from the A. as appears by the striking of the string open.
Secondly, part the distances from N. to A. in three parts, then the first part gives you the seventh fret from the Nut, making a Diapente [fifth]; in that place also set a prick, and upon it the letter H.
Thirdly, divide the distance from the letter H. to the letter A. in eleven parts, two of which parts from A. gives the first fret; note that with a prick, and set the letter B. thereon, which makes a Semitone.
Fourthly, divide the distance from H. to the letter A. in three parts, one of which parts from A. upward shows the second fret; note that with a prick, and set the letter C. upon it, which makes a whole Tone from A.
Fifthly, divide the distance from N. to A. into two parts; there the first part shows you the fifth fret, sounding a Ditessaron [fourth]: in that place also set a prick, and upon it the letter F.
The sixth fret, which is a G., must be placed just in the midst betwixt F. and H., which makes a Semidiapente [tritone].
Seventhly, divide the distance from the letter B. to A. in three parts, which being done, measure from the B. upwards four times and a half, and that will give you the third fret, sounding a Semiditone [minor third]: mark that also with a prick, & set thereon the letter D. then set the fourth fret just in the middle, the which will be a perfect ditone [major third]: then take the one third part from B. to the Bridge, and that third part from B. maketh I. which sounds Semitonium cum Diapente [minor sixth], then take a third part from the Bridge to C, and that third part maketh E. which sounds Tonus cum diapente, or an Hexachordo maior [major third].
Then take one third part from D. to the Bridge, and that third part from D. makes L. which sounds Ditonus cum Diapente [minor seventh].
Now take your LVTE, and lay it upon a table upright, and set the Ruler edgewise, between the nut and the bridge, and thereby set little marks upon the neck of the Instrument even with those on the ruler, because those are the places on which your frets must stand.
Thus have you the perfect placing of your ten frets, which takes away that scruple by which many are deceived, when they say the frets are false. Note here also, we do not try the frets, as we try the strings: but (now knowing their places) size them rightly, for which any kind of string will serve, I meane whether they be true or false, new or old, only take heed that you set not a great fret where a small one should be, & so by contrary : for every fret serves as a Magade; therefore do this: let the two first frets nearest the head of the Instrument (being the greatest) be of the size of your Countertenor [F course], then the third and fourth frets must be of the size of your great Meanes [A course]; the fifth and sixth frets of the size of your small Meanes [D course]: and all the rest sized with Trebles [G string]. These rules serve also for Viols, or any other kind of Instrument whereon frets are tied.
Note: I have no clue what a "Magade" might be. If anyone is familiar with this word, please let me know what it means!