My son, I’ve perceived your great ability to learn science, so consider yourself gifted now for I will teach you of that what is within the numbers and proportions. Consider I pray for you, alone then and afterwards in your special way, as having learnt these certain special evidences of the treaties of the astrolabe. 

As a philosopher once said "he wraps him up in his friendship, with that but which condescends to the rightful praise of his friend”, therefore in as much as I know the latitude of oxford, upon which, by meditation on a technique told now, I propose to teach you a certain number of conclusions (appertaining to the same instrument). 

I myself see for certain in this, these causes for a conclusions foremost. The first cause is to trust well that all the conclusions that are discovered, or else possibly might be, in so noble an instrument as is this astrolabe, are unknown in part to any mortal man in this region, as how so I do suppose of the same such conclusions. Another cause is that even a soothing grace said by anyone will be for some a conclusion that by all things performed at her behest, is something about them that’s too hard to conceive.

By this treaties, divided in 5 parts, I will show what is known in the full light and rules of naked English words, which in Latin you cannot know fully, my son. Never the less suffice it to say that these true conclusions in english as well sufficed for reason with the noble clerks of the Greeks. These very same conclusions were said in greek mind you, and to Arabians in arabic, and to Jews in hebrew, and to the latin folk of Italy. Which latin folk had first said thereof, out of all the other diverse languages, and written of them in their own tongue, that is also said alike in latin; I don’t know. God would that in all these languages and in many more ways than these, know that we do conclude to sufficiently learn and teach by diverse rules, and as rightly diverse as paths that lead diverse folk the right way to Rom. 

Now will I pray concretely that every person that reads or hears this will discretely excuse my rude editing, and superfluous use of words. The reason being for any heavy sentences (and lack of structural form), is only for a standard of a curious child in learning, and lest he forget it all at once. Lo and behold to show more than this in the light of day, that is which my english says true in conclusion on these mater, and not only but to serve as truth in future with as many a subtile conclusions as forthrightly possible. So will been shown either in latin or in any further communication of this treaties of the astrolabe, I can say thankfully. For I pray so that God saves the King, who is lord of this language, and that in all that his faith bears in obedience, in every degree more and less. So consider well that I am no  compiler of the labour of old astrologies, mere set to usurp the labours, as have worked hard to translate a lot into english for this doctrine, and so like a sword only more shall I shear ones envies.

Prima pars.  The first part of this treaties shall state the figures and the members of the astrolabe. With this alone you shall have greater knowing of the instrument.

Secunda pars. The second part shall teach the practical workings of the aforesaid conclusions about this small and portable instrument called the astrolabe, as far fetched and narrow as they may be. For well does every astrologer know that the smallest fractions can be shown in this instrument, as are needed in the most subtle tables calculated for any cause.

Tertia pars. -The third part shall contend diverse tables of longitudes and latitudes of stars fixed for the astrolabe, tables of the declinations of the sun, tables of longitudes of cites and towns, and tables as well for the governance of a clock. All as so to find the altitude of a meridian and many other notable conclusion known by the calendar after the revered efforts of clerks, Friar J. Somes and Friar N. Lenne.

Quarta pars. -The fourth part shall describe in theory a declaration of the causal motion of the celestial bodies. The fourth part will show a table of the motion of the moon from hour to hour every day and in every sign too, called the almanac. This table follows with a law sufficient to teach you as well the manor of the operation of this all, so in conclusion as to know yourself in detail how the astrolabe shows the moon arising on the horizon by the set latitudes, and by its degree of the zodiac, and more so the arising of any of the planets on the elliptical line.

Quinta pars. -The fifth part shall be an introduction, after the statutes of medicine, for which thou must learn a great part of the general rules of theory in astrology. In which fifth part shalt thou find tables of equations of houses after the latitude of Oxford, and tables of dignities of planets, and other interesting things, that by God we would vouch safely by and to say for your maiden mother too, I behest.

Here begins the description of the astrolabe.

1. Your astrolabe has a ring, place it on the thumb of your right hand for taking the height of things. Pay attention now for from hence forth I would call the height of any thing that is taken by the rule ‘the altitude’, without more words.

2. This ring connects to your astrolabe set in mode. Fixed hereto so as for readily roaming a space, you’ll not disturb the instruments settings, when hanging onto it away from its centre.

3. The mode of the astrolabe is set on its thickest plate, transfixed by large rings that interprets on the compound plate, any of the diverse alignments, and when you’ve changed its dial otherwise appearing as a net or a looped web.