<p style='text-align: justify;'>Conradus Dasypodius (c. 1530-1600) was educated at the universities of Louvain and Paris. He became Professor of Mathematics at the Strasbourg Academy (promoted to a university in 1566), and his publications reflect his pedagogical interests, such as his edition of Euclid's <i>Elements</i>, his dictionary of Greek mathematical terms, and his <i>Institutionum mathematicarum erotemata</i>, a question-and-answer manual of mathematical definitions. As a humanist, he was also interested in translating (from Greek into Latin) the works of Hero of Alexandria, Theodosius of Bithynia, and Autolycus of Pitane. This work, <i>Heron mechanicus</i>, is a short book extolling the virtues of the discipline of mechanics, and is well-known for its title-page, which shows the astronomical clock in Strasbourg Cathedral, designed by Dasypodius and built by the clock-makers Isaac and Josias Habrecht. The artist Tobias Stimmer was commissioned to paint the decorative elements. The title of the work, 'Heron the mechanic', refers not to Hero of Alexandria but to the tenth-century 'Hero the Younger' of Byzantium, who wrote on surveying. In the first part of the book, Dasypodius, in typical humanist fashion, stresses how the Ancients had cultivated and esteemed the mechanical arts, which were also supported and practised by kings and princes. Influenced by Vitruvius, Dasypodius divided mechanical knowledge (<i>scientia machinalis</i>), the knowledge of making machines, into 'logical' and 'chirugical'. The former requires mastery of the learned books of the Ancients on mathematical and natural philosophical topics, ingenuity and cleverness, before applying one's hands to making machines. The latter involves skilful deployment of manual labour, without any understanding of the mathematical principles involved. Dasypodius praises ancient authors, such as Archimedes and Hero of Alexandria, who had advanced 'logical' mechanical knowledge. This neatly reflects Dasypodius' view of himself as it comes through in the second part of the work, which describes the astronomical clock. There he explains the design of the clock and defends the value of mechanical knowledge, pointing out how he 'sweated much in instructing untutored craftsmen and illiterate workers' to build the clock. The Strasbourg clock was famous for its precision and numerous allegorical figures. It also contained one of the earliest portraits of Copernicus. The lower part of the clock contains three tables. The lateral ones, numbers 2 and 3, contain the diagrams (<i>diagrammata</i>) of the eclipses of the Sun and Moon for the next thirty-two years, with optical, geometrical and astronomical figures filling in the vacant space. The middle table, number 4, shows a wheel, which is a 'perpetual' calendar for the next 100 years, showing the precession of the equinox, the movable feasts, the dominical letters and the leap years. In the four corners of this table, four monarchies are depicted. Two statues flank the disc ' one of Apollo, marking out the current day with a spear, and one of Diana indicating the day opposite it. In the centre, a map of the German Rhinelands and a topography of Strasbourg are shown. The tables of eclipses, calculated from the <i>Prussian</i> and <i>Alphonsine Tables</i> for the meridian of Strasbourg are reproduced in the box, so that it could be better seen. Above the wheel, a statue of the seven planets appears for each weekday (e.g. Saturn for Saturday, the Sun for Sunday), flanked with images (numbers 5 and 6) of the Creation, original sin, redemption and resurrection. Above the planetary figures is a small clock, showing the quarter-hours and the minutes, with a boy on each side. One indicates the number of hours with a sceptre, the other turns the sand clock at the sound of the hourly signal bells; in the top corners, two lions are placed (number 8) holding the insignia of the city of Strasbourg. In the middle section of the clock is an astrolabe (number 9), with hands for the Sun and the Moon and the remaining planets. The hands show the mean position of each planet in the zodiac. In the four corners outside the astrolabe, the four seasons and the four ages of man are depicted. Above the astrolabe, at number 10, is a disc that shows the monthly phases of the Moon. At number 11 are the statues of the four ages, which indicate a quarter-hour by the sound of bells; thus a boy by one stroke of the bell, a youth by two, a man by three, an old man by four, the fourth and last part of the hour. At number 12, the statue of Death appears at the striking of the hour, with its own bell, and the statue of the Saviour meets the individual statues of the four ages, to signify redemption. On the top of the clock, at number 13, bells strike the psalm songs. Above it is a cock, made 200 years earlier, that crows to remind men of Peter's denial of Christ. This is shown at number 14 at the top of the tower, shown from the side at the left of the clock in the woodcut. The side panels of the tower were painted with various figures: Urania (number 15), Colossus (number 16), Nicholas Copernicus (number 17), and the three fates, Lachesis, Clotho and Atropos (numbers 18 to 20). Thus, this clock is, according to Dasypodius, a complete description of time (<i>absoluta descriptio temporis</i>), showing the minutes, the quarter-hours, the hours, the weeks, the months, the seasons, a year, a century, the beginning and the end of the World.</p>
