abbess: The female form of abbot. The superior of a convent. 
abbot: The superior of a monastary. From the Syriac, meaning father. The term was used from the 5th century. 
Accademia dei Lincei: The Lyncean Academy was founded by Frederico Cesi, and it supplied scientists and mathematicians with room, board, books, and laboratory equipment to study nature. Galileo was inducted into the academy in 1611.
archbishop: A bishop of the highest rank who presides over an archbishopric or archdioscese. 
armillary sphere: An instrument consisting of an arrangement of rings, all of which are circles of the same sphere, used to show the relative positions of the celestial equator, ecliptic, and other circles of the clestial sphere. See Medici article. 
atmospheric refraction: The change in direction of a ray of light as it passes from space into the atmosphere. This causes celestial objects to appear to be in a location different from their actual ones.
Benedictine Order: The Order of Saint Benedict is a confederation of congegations of monks and nuns, not a centralized religious order. Each monastary is an autonomous community following the rule of Benedict of Nursia. 
bishop: The priest who acts as the highest religious official in a diosces. One of the principal functions of the bishop was to celebrate the Eucharist. 
camera obscura: A darkened boxlike device in which images of external objects, received through an aperture, are exhibited in their natural colors on a surface arranged to receive them. 
canon: One of a body of dignitaries attached to a cathedral or a collegiate church, or a member of certain religious orders. 
cardinal: High ecclesiastic appointed by the pope to the College of Cardinals and ranking above every other ecclesiastic but the pope. 
Carmelite Order: The Brothers of the Blessed Virgin Mary of Mount Carmel is one of the mendicant orders originating on Mount Carmel in Israel. 
Collegio Romano: The main Jesuit seminary, founded by Ignatius de Loyola in 1551. It received the right to grant doctorates along with other privileges enjoyed by other universities through papal bulls in 1552 and 1556.
Curia Romana: The body of congregations, offices, permanent commissions, and such that assist the pope in the government and administration of the church. 
Counter Reformation: As dissenting groups split off from the Catholic Church in what came to be known as the Protestant Reformation, the Church began a series of reform measures of their own. These reform measures aimed to keep Church members from becoming Protestants, and were known as the Counter Reformation.
cyclodial: A cycloid is a curve generated by a point on the circumference of a circle that rolls, without slipping, on a straight line. 
deacon: The deacon does not baptize or bless or offer the Eucharist, but gives the sacrament to the people when a bishop or presbyter has offered. He acts as an assistant to the priests, but is not a priest himself. The deacon also visits the sick and arranges for burials. 
Dominican Order: The popular name for the Order of Friars Preachers. The order was founded by Domingo de Guzman (known as Dominic) between 1215 and 1221. Like the Franciscans, the Dominicans were mendicant friars. 
ecclesiastic: A member of the clergy or other person in religious orders. 
ecliptic: The great circle formed by the intersection of the plane of the earth's orbit with the celestial sphere, or the apparent annual path of the sun in the heavens. 
Florence: A wealthy city in the Tuscany region of Italy. Florence was ruled in the 15th century by the Medici family, who acted as patrons to many writers, artists, and engineers. Galileo was born in Florence in 1564.
fra: A title of address for a friar or monk, a shortened form of frate, brother. 
fulcrum: The support, or point of rest, on which a lever turns in moving a body. 
gimbal: A contrivance, consisting of a ring or base on an axis, that permits an object, as a ship's compass, mounted in or on it to tilt freely in any direction, in effect suspending the object so that it will remain horizontal even when its support is tipped. 
gout: An acute, recurrent disease characterized by painful inflammation of the joints and by an excess of uric acid in the blood. 
Gregorian calendar: The most recent in the attempts to make the calendar year correspond to the natural year. The Gregorian calendar (instituted in 1582 by Pope Gregory XIII) corrected for the loss of one day every 128 years by dropping three leap years every 400 years. Century years were leap years only if evenly divisible by 400.
harmonic oscillator: Each oscillation has a frequency that is an integer multiple of the same basic frequency. 
Inquisition: A permanant institution of the Church charged with the eradication of heresies.
isochronous: Equal or uniform in time. 
Jesuits: The popular name for the monastic order called the Society of Jesus. The order was founded by Ignatius de Loyola in 1534, and was recognized by the pope in 1540. The mission of the Jesuits was in three areas: teaching, service to the nobility, and missionary work in foreign lands. Their greatest mark was made in education, and the Collegio Romano was their primary seminary.
lunar librations: The real or apparent oscillatory motion of the moon. 
Lyncean [Lincean] Academy: See Accademia dei Lincei.
margrave: The hereditary title of the rulers of certain European states. 
opposition: The situation of two heavenly bodies when their longitudes or right ascensions differ by 180? The moon is in opposition to the sun when the earth is directly between them. 
papal bull: Essentially a letter from the pope to all Christendom, a bull was so called because a lead bulla or seal was attached to it by a cord. 
papal legate: An ecclesiastic delegated by the pope as his representative. 
parallax: The change in the position of an object in the heavens due to the orbit of the earth. Observable parallax in the fixed stars is a proof of the rotation of the earth around the sun. See this explanatory diagram.
penitentiary: A tribunal in the Curia Romana, presided over by a cardinal, having jurisdiction over certain matters, as penance, confession, dispensation, absolution, and impedimens, and dealing with questions of conscience reserved for the Holy See. 
peripatetic: Walking or travelling about. Of or pertaining to Aristotle, or the Aristotelian school of philosophy, who taught philosophy while walking in the Lyceum in ancient Athens. 
polymath: A person of great learning in several fields of study. 
prior: An officer in a monastic order or religious house, sometimes next in rank below an abbot. 
Procurator General: A person, as a deputy, attorney, or agent, employed to manage the affairs of another. 
Prothonotary Apostolic: A member of the first college of prelates of the Roman Curia. Charged chiefly with the registry of pontifical acts and canonizations. Also an honorary title for certain other prelates. 
provincial: The head of an ecclesiastical province, or a member of a religious order presiding over the order in a given district or province. 
quadrature: Those points or moments at which a half moon is visible. More generally, it is the situation of two heavenly bodies when their longitudes differ by 90?  (tycho brahe)
rector: An ecclesiastic in charge of a college, religious house, or congregation. 
retrograde planetary motion: At times the planets appear to be moving opposite to their direction of rotation. This is caused by the effect of the rotation of the earth on our observations of the other planets.
Savonarola, Girolamo: A Dominican friar, prior of the convent of San Marco in Florence, Savonarola believed that he was sent as a watchman for God to warn people of impending doom. His power was such that when the Medici family was expelled in 1494, he ruled the city and became a major power in Italy. In 1496, he turned against the pope, after the pope attempted to control the prior's power by offering a cardinal's office. In 1497, the pope excommunicated Savonarola. Savonarola continued to practice as a priest, refuting the order. In the end, Savonarola was tortured and in 1498 was hanged. 
sidereal period: A period determined by or from the stars. 
synod: An assembly of ecclesiastics or other church delegates, convoked pursuant to the law of the church, for the discussion and decision of ecclesiastical affairs.  A council within the Church. Diocesan councils consisted of the presbyters of a dioscese meeting under the presidency of the bishop. Provincial councils consisted of all the diosces in an ecclesiastical province, with the provincial in the role of the pre sident over the bishops of the province. Plenary councils were councils of several provinces. Patriarchal councils were of the provinces united in one patriarchate. The provinces in a country could form a national council. General councils could be of the East or West, or of the whole Church. Finally, Ecumenical Councils were those whose decisions were accepted by the Church as a whole. 
Tuscany: A region of Italy in the west, north of Rome and south of Genoa. Florence is located in Tuscany.
vicar: An ecclesiastic representing the pope or bishop, a deputy. 
vicariat: The office or authority of a vicar. 
©1995 Al Van Helden