MEDIUM-SIZED QUADRANT

OF AZIMUTHAL BRASS

original: "Quadrans Mediocris Orichalcicus Azimuthalis"

...toward the upper part of the tree, which is the sterile part. By this we imply that nothing can make a person truly blessed or grant eternal immortality except the merit of the Son of God, Christ the Redeemer, and the observance of His doctrine and life. I chose to explain these individual points here—though perhaps they are a bit beside the main point—because of the accompanying illustration. On the other side of the Quadrant, a CanonA mathematical table or set of rules used for calculation. has been engraved with ciphers numbers, which shows with very little effort what the individual points of the Nonnian DivisionA system devised by the Portuguese mathematician Pedro Nunes (Petrus Nonnius) using concentric arcs to measure fractions of a degree; it was a precursor to the modern Vernier scale. (which I mentioned earlier) represent in terms of the altitudes being sought.

EXPLANATION OF THE CONSTRUCTION AND USE.

The use of this Quadrant is for taking the AltitudesThe angular height of a celestial body above the horizon. of the stars and the "Luminaries" the Sun and Moon; this is done when the highest precision is not required, such that knowing the measurement within two or three minutes of a degree is sufficient. One should then direct the plane of the Quadrant toward the star to be observed and properly adjust it by its screws, as was said before, until the plumb lineA weight suspended from a string used to ensure the instrument is perfectly vertical. shows that everything is correctly positioned. The...