Modern Geology

In 1785, James Hutton, widely seen as the father of modern geology, published his paper Theory of the Earth. In this popular paper, Hutton discusses many of the concepts Leonardo da Vinci had hypothesized hundreds of years earlier. Both men refute the Biblical flood as the foundation for formations we know today and assert Earth must be much older than what was previously believed.

Da Vinci and Parabolic Mirrors

In a note and sketch dating back to approximately 1515, da Vinci references some of the ideals and machines Brunelleschi invented back when he was constructing the duomo. The sketch and note related to some of da Vinci's work on designing parabolic mirrors and he says, "Remember the solders used for soldering the ball on Santa Maria del Fiore (Florence Duomo)." This artifact exemplifies the inspiration Leonardo drew from Brunelleschi and his machines and further proves Leonardo's involvement with the construction of the duomo.

Source: Leonardo da Vinci in Florence: On the Lantern. (n.d.). Retrieved from https://erenow.net/biographies/leonardo-da-vinci-the-flights-of-the-mind...

The death of Brunelleschi

On April 15, 1446, Filippo Brunelleschi, the overseer of the reconstruction of the Florence Duomo, died. His architecture and the machinery he designed to make it possible made a lasting impact not only on Florentine architecture, but inspired Leonardo's love and interest in machinery, physics, and engineering. The death of Brunelleschi also meant that someone else had to be hired to create and place the lantern, bronze ball, and cross at the top of the duomo. Verrocchio was hired for the job, meaning that Leonardo was able to work even closer on the duomo as he was an apprentice of Verrocchio.

Source: Mueller, T., & Yoder, D. (2017, September 19). Brunelleschi's Dome. Retrieved from https://www.nationalgeographic.com/magazine/2014/02/Il-Duomo/

Milan Cathedral Design

In 1487, officials in Milan asked architects to submit design ideas for a tiburio, lantern tower, for the top of their under-construction cathedral. Leornardo collaborated with architects Donato Bramante and Francesco di Giorgio on the design. He worked to design a double-shell dome, very similar to the one in Florence's cathedral. However, Leonardo favored a more traditional style, so he did not try to make his dome match the gothic design of the rest of the Milan cathedral. As a result, his designs were rejected and he eventually withdrew his application. The winning designs came from Francesco di Giorgio, and architect from Siena, who Leonardo worked with on other projects later on. 

Source: Isaacson, Walter. “Vitruvian Man”. Leonardo Da Vinci. Simon & Schuster, 2017

Photo Source: http://www.leonardo-da-vinci.net/architecture/

Annunciation by Leonardo Da Vinci

Annunciation by Leonardo da Vinci

Annunciation is generally considered to be one of Leonardo’s earliest works, created during his time as an apprentice in the studio of Andrea del Verrocchio. Dating from around 1472, this painting, made with tempera and oil on a wood panel, depicts one of the most popular subjects for artwork throughout this period. The left side of the composition is dominated by the archangel Gabriel who is seen kneeling and holding a bundle of white lilies, the symbol of the virgin. Opposite of Gabriel, Mary is seen acknowledging the arrival of the angel from behind a marble bench, where she was reading. The event is set in an earthly, natural environment, with landscape painting in the background that is characteristic of da Vinci’s later works. 

“Annunciation.” Artworks, Uffizi Galleries, www.uffizi.it/en/artworks/annunciation.

Image Retrieved from Wikimedia Commons, fair use

Andrea del Verrocchio

Portrait of Andrea del Verrocchio

Andrea del Verrocchio was a 15th century Italian sculptor, painter and goldsmith. Very little biographical information is known about the early life of Verrocchio, but it is thought that he studied painting with Sandro Botticelli under the Renaissance master Fra Filippo Lippi. He was also trained as a goldsmith, and in fact took the name "Verrocchio" from his master.  Verrocchio’s rise to artistic prominence is largely owed to the patronage of the Medici family, who supported his career as a sculptor. His reputation across the country led many great artists to study in his studio, perhaps most importantly young Leonardo da Vinci.

Passavant, Günter. “Andrea Del Verrocchio.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 1 Feb. 2019, www.britannica.com/biography/Andrea-del-Verrocchio.

Image Retrieved from Wikimedia Commons, fair use

Anatomy Before da Vinci

Galen was a Greek physician, philosopher, and author that practiced around 150 A.D. He was a well-known physician and served many emperors in the Roman Empire as a personal physician. Galen complied work from original anatomist such as Hippocrates and added his own discoveries and beliefs to write over 20,000 pages of anatomical study. He had a strong belief in experiments and observation, instead of believing what has always been written. This belief helped him make advancements in his career including:

Identifying 7 of 12 cranial nerves

Proving the kidneys make urine

Diagnosing using a patients’ pulse and urine sample

Discovering the heart has 4 valves

But Galen’s education was still based on old knowledge and he had flaws in his studies such as the belief that an imbalance of humors caused disease and that the liver was the center of the great vessels in the body. Despite this, Galen’s anatomical studies stayed as primary belief for about 1500 years, until scientist like Leonardo da Vinci began to challenge his beliefs. Da Vinci’s artistic ability and engineering studies assisted him in attempting to bring in a new era in anatomical studies, though none of his work was published so little impact was made from all his work. The anatomical revolution was contributed more to Andreas Vesalius.

Sources:

Stewart, D. (2014). Galen. Famous Scientist: The Art of Genius.

Picture from Wikimedia http://catalogue.wellcomelibrary.org/record=b1165357

Childhood Exploration

Leonardo da Vinci grew up in a small Tuscan town in the lower valley of the Arno River, allowing him to explore the many fossil-containing caves at the foothills of the Alps. From a young age, da Vinci questioned the popular Biblical flood theory, instead using logical reasoning accompanied by his own observations to come to the correct conclusion on geological formations hundreds of years before these concepts were popularized.

da Vinci's First Sketch

Leonardo da Vinci’s first known work ("The Hills of Tuscany") is from 1473 when he was 21 years old. The sketch is believed to be inspired by the Arno Valley where da Vinci grew up. Although da Vinci never published his geological theories, his works were geologically correct; he understood the geological processes that shaped our mountains and valleys hundreds of years before the public.

The Flexible Bow Catapult

Representative Depiction of Dionysius' Catapult

With the specificity of ancient Greek tactical warfare as a quest to conquer cities of breadth, depth, and optimized defense, the rulers of Greek colonies during the fourth century B.C. era became increasingly interested in improving their range and decimating force of weaponry in their lustrous goals to secure any and all sieges or battles.  Thus, the commencement for designing a weapon to redefine infringing warfare began in 399 B.C. when Dionysius the Elder, the Greek ruler of the colony of Syracuse in Sicily, issued a declaration to produce new novel weapons, one of which was the infamous catapult.

Although categorized as the first catapult recorded through conventional documentation, these ancient catapults more closely resembled the common draw-bows of soldiers during this era and utilized what has now been coined, “The Flexible Bow Mechanism,” an apparatus which generates power through tension created by movable sliders.  Thus, these mechanical bows were responsible for launching arrows through the compositionally conglomerative use of composite wooden ores, tension fibers of animal sinew, and wooden compression horns.  Contrary to the depiction of stereotyped catapults, one should note that this initial design remained attached to the human subject as, descriptively, this preliminary design was to be worn across the shoulders of soldiers on the battlefield and strategically placed along a surface once one’s destination was secured.  However, records also suggest that the soldiers of Syracuse were also known to have constructed mobile siege towers that were to overlook enemy city walls and utilize flexible-bow catapult to provide heavy aerial fire.  The design also received notable adjustments in its inception.  This included the preferred use of animal sinew to human or horsehair for optimized elastic tension, the addition of linear ratchets alongside the weapon’s main stock which increased the resistive force of the bow, and the use of a circular rachet to allow winches to be used in the drawing of the highly compressed bow. 

Furthermore, the weapon’s highly optimized precision was said to have made the catapult an attractive device for the ruling Greek commissioners.  Thus, due to the increased precision of the bow, the size of the design quickly increased to favor more impactful assaults.  While no longer permitting the mobility of the device by mere human strength, the catapult required a lower pedestal for stability purposes.  To facilitate this change in design, the ancient engineers of Syracuse were recorded as the creators of the first iteration of the universal joint, a mechanism which is commonly thought to originate in the 16^th and 17^th century by either Girolamo Cardano or Robert Hooke.  While there is not any official recording for the approximate range of these early catapults, these weapons were said to have been able to utilize arrows nearly two meters long and decimate enemy forces with deadly accuracy.

Sources:

History of Catapults - Physics of Catapults. (n.d.). Retrieved May 6, 2019, from https://sites.google.com/site/physicsofcatapults/home/history-of-catapults

Yurtoğlu, N. (2018). Http://www.historystudies.net/dergi//birinci-dunya-savasinda-bir-asayis-sorunu-.... History Studies International Journal of History, 10(7), 241-264. doi:10.9737/hist.2018.658

Ctesibius’ Catapult and The Repeating Catapult

Representative Depiction of Ctesibius' Catapult

With the domination of the catapult now solidified in the social and pollical hierarchies of ancient civilizations, efforts to further improve the catapult were attempted.  Beginning with Ctesibius of Alexandria in mid-3^rd century B.C., this ancient engineer was credited with an attempt to use airtight cylinders and compress bronze springs to pivot rigid firing arms to a point of optimized tension.  However, with the compression of air and the introduction of piston friction, unexpected fire and smoke emitted from the catapult’s cylinder were responsible for decreasing both the structural rigidity, as the carpenter’s glue used to construct the device was heated, and range of Ctesibius’ catapult.

Furthermore, simultaneous development also begun on what is referred to as the “Repeating Catapult” by Dionysius of Alexandria in an arsenal in Rhodes.  The repeating catapult, an invention which employed mechanisms not reintroduced until the Renaissance, was a theoretically and idealized model with the intention to automatically fire arrows until a revolving drum containing ammunition was emptied.  Essentially proposing a model for an ancient machine gun, this catapult was most notable for its inclusion of a flat-linked chain drive system which was to be later popularized and accredited to Leonardo da Vinci during the early 1500s.  This flat-link chain drive, resembling that used on a modern bicycle chain, was to run over a five-sided prism and repeatedly turn a winch to release and draw the main stock of the weapon.  Regarding da Vinci’s later involvement with the chain-drive device, this chain drive mechanism precisely embodies what he idolized as the fundamental relationship between an object’s mass and velocity while investigating the basic laws of perpetual motion.  Ultimately, this design was never developed due to its paradoxical ability to only fire concentrated shots at a minuscule range of 200 meters that could not be dispersed away from one central target before running out of ammunition.

Sources:

Rossi, C., & Russo, F. (2010). A reconstruction of the Greek–Roman repeating catapult. Mechanism and Machine Theory, 45(1), 36-45. doi:10.1016/j.mechmachtheory.2009.07.011

Yurtoğlu, N. (2018). Http://www.historystudies.net/dergi//birinci-dunya-savasinda-bir-asayis-sorunu-.... History Studies International Journal of History, 10(7), 241-264. doi:10.9737/hist.2018.658

Antikythera Mechanism

This is the first ever recorded use of clockwork, and dates back to Ancient Greece, It is speculated to have been used to predict astronomical events such as eclipses, or perhaps to track the 4-year cycle of ancient olympic games. 

After detailed imaging, it is suggested that the original mechanism contained 37 gears to follow the sun and the moon, to predict eclipses,

Archytas Creates the Flying Pigeon

Archytas, a Greek philosopher who lived between 428 BC and 347 BC, is believed to be one of the first people to investigate the idea of flight. He created a steam-powered flying pigeon sometime during his lifetime; however, the exact timing of this invention is unknown. The naming of this device came from the fact that it resembled the shape of a pigeon: wings on either side and a pointed front like a beak. The pigeon contained an opening at its rear which was connected to a heated boiler. The steam produced by the heated water caused an increase in pressure that produced the force required to eject the pigeon, which was reported to fly for several hundred meters.

Source (text and image):

Reese, M. R. (2014). The steam-powered pigeon of Archytas—the flying machine of antiquity. Ancient Origins. Retreived from https://www.ancient-origins.net/ancient-technology/steam-powered-pigeon-archytas-flying-machine-antiquity-002179.

The Geocentric Model

Geocentric model vs Heliocentric model

Ancient Greek Philosophers such as Aristotle, Plato, and others, porposed the geocentric model of the universe, claiming that the Earth was the center of the universe and all the planets and the stars revolved around us in concentric circles.  This theory was then ammended by Ptolemy to account for the changes in certain planet's luminosity.  He determined that, rather than the planets and the sun simply be orbiting around the Earth, they would simultaneously be moved by a system of two spheres creating a second path of circular motion (shown in the below link).  This explaination was widly accepted for over a thousand years, including the time da Vinci lived.

https://www.youtube.com/watch?v=wGjlT3XHb9A

The Baptism of Jesus

Baptism of Jesus

Along the River Jordan in Palestine, Jesus was baptized by St. John the Baptist. Baptism is the first Christian Sacrament and is the pouring of water over one’s head. Baptism cleanses the receivers of their sins, including Original sin, and the welcomes them into the Christian Church. The Baptism of Jesus is the first Baptism mentioned in the Bible, thus instilling the sacrament, and giving Christian’s an example that is still followed today. Jesus' Baptism is also the first time the Trinity (The Father, The Son and The Holy Spirit) is seen all together in the Bible. All three persons of God were present at the Baptism, showcasing the significance of the event. As Jesus was baptized the heavens opened up, a dove (the Holy Spirit) came down and rested on Jesus, and the Father's voice was heard from the Heavens. 

Source: https://www.compellingtruth.org/Jesus-baptized.html

Image retrieved from WikiMedia Commons: https://commons.wikimedia.org/wiki/File:Baptism_of_Christ_Baptistery_Florence_copy.jpg

The Birth of Vitruvius (80 BC)

Vitruvius

Vitruvius was born around 80 BC. He was a famous military engineer and architect. While most of his life is undocumented (including exactly where he lived), it is known that was alive while Italy was under the rule of the Roman Empire. He is most known for his theories about proportions in temples and the human body, including the first recorded measurements that would inspire da Vinci to sketch his Vitruvian Man.

Source: Isaacson, Walter. “Vitruvian Man”. Leonardo Da Vinci. Simon & Schuster, 2017.

Photo Source: https://www.thefamouspeople.com/profiles/vitruvius-34320.php

Verge and Foliet Clock

The animated motion of a Verge escapement

The Verge and Foliet are the first escapements to be used to construct the first mechanical clocks. Using a notched wheel and a rod wih two plates, the rotational motion of the wheel can be controlled and regulated into small ticks. These escapements were used in all clocks until the pendulum was introduced, and da Vinci used these mechanisms in his own clockwork.

Oil Paint as a Medium

Up until the 15th century, the most common medium for painting was tempura paint. Tempura paint dries very quickly, meaning artist using tempura could not easily blend colors. Tempura paintings have been found from about 3000 BC. on early Egyptian sarcophagi decorations, thus showing how long tempura had been the most common medium. This shows monumental the transition from tempura to oil paint truly was. Oil paint began to make its way to Europe in the 12th century but was not widely adopted until the 15th century. The appeal to oil paint was that it dried slowly which allowed artist to continually work the paint. This allowed for artist to blend the paints thus allowing for softened transitions between colors, and results in a more accurate depiction of shading. The technique spread to Italy in the late 1400's starting in Venice and by 1540 oil painting completely dominated as the most popular medium - tempura was no longer being used at all. Oil paints often only came in a few premade colors, there artists had to mix small amounts of colors to create more shades, often done on a wooden palette. The crescent shaped wooden palette that is typically a symbol of an art, is in reference to oil painters. 

Sources: https://en.wikipedia.org/wiki/Tempera    

 https://en.wikipedia.org/wiki/Oil_paint

 https://en.wikipedia.org/wiki/Oil_painting

Image retrieved from Wikimedia Commons:  https://commons.wikimedia.org/wiki/File:Cadmium-paints-amy-lavine.jpg

Wars in Lombardy:

Italy in 1494

The wars in Lombardy were a series of struggles between the Republic of Venice and the Duchy of Milan, leading to the five major Italian territorial powers that make up the map of Italy until the Italian Wars (i.e., Venice, Milan, Florence, Naples, and the Papacy). The wars ravaged the economy of Lombardy and weakened the power of Venice. The Peace of Lodi in 1454 brought 40 years of comparative peace to Northern Italy. This is the time of the Medici rule of Florence, first Cosimo de’ Medici, then Piero “the Gouty,” then Lorenzo Il Magnifico.  The death of Lorenzo marked the end of the Golden Age of Renaissance Florence. Both Leonardo da Vinci and Michelangelo Buonarroti were active (and tied to Lorenzo) during this period. In 1428, Venice acquired Brescia and Bergamo as a result of this struggle.

The Fall of Constantinople

The fall of Constantinople marked the end of the Byzantine Empire after ten centuries of war. The Ottoman Turks defeated felled the city and ended the European Middle Ages. 

The Byzantine Empire had been a bastion of Christian Europe facing Muslim Asia. The Ottoman Turks were expanding their empire and saw Constantinople as a center of the rival Christian faith and a symbol of imperial power. 

Constantinople had held off many attempts to destroy or capture it but was declining in power over the years. Mehmed II set out to take the city in the spring of 1453 and used the sea to gain access to the city. Initial attacks failed, but on May 29th, Mehmed launched attacks from the sea and the land simultaneously.  The Ottomans were finally able to overwhelm the defenses due to the use of gunpowder-powered cannons. After gaining access past the walls, the Ottomans killed the emperor and massacred the citizens. 

Mehmed rode a white horse down streets that ran with blood to Hagia Sophia, the city's famed cathedral. He used the cathedral as a mosque to say prayers of thanks for the victory. 

The fall of Constantinople was important because it was a watershed moment in military history. The city had defended itself with walls and ramparts since ancient times. These fortifications were used as the model of many later cities. The end of the Byzantine Empire marks the end of the Medieval period.  

Bunting, Tony. “Fall of Constantinople.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 22 May 2018, www.britannica.com/event/Fall-of-Constantinople-1453.

“Fall of Constantinople.” Wikipedia, Wikimedia Foundation, 2 May 2019, en.wikipedia.org/wiki/Fall_of_Constantinople.

Paolo Uccello's The Hunt in the Forest

Paolo Uccello was an Italian painter who died just before the Renaissance. In one of his last paintings titled The Hunt in the Forest, we can see perspective beginning to appear in art. Uccello's piece also is a great example of how plants and trees were painted during the pre-Renaissance. His plants show variation and stand out from each other, but they still don't look like a real tree. Uccello's plants in the foreground also still maintain the symbolic look rather than the realistic look that would appear during the Renaissance.

Image from Wikimedia Commons, commons.wikimedia.org/wiki/File:Paolo_Uccello_The_Hunt_in_the_Forest.jpg. This image is under common domain and free use.

Verrocchio and DaVinci paint 'The Baptism of Christ'

"The Baptism of Christ" was commissioned to Verrochio by the monks of San Salvi, a church located in Florence. It is thought that the painting was worked on by Verrocchio, DaVinci, and possibly one other older artist. At the time it was very common for artist to paint the main figure and leave the secondary figures to their pupils. It is thought an older artist may have painted the dove and the hands for the appear to be less developed than the rest of the painting. DaVinci is known to have painted the left angel in the painting as well as Jesus' figure and parts of the background.  In the background it can be seen that DaVinci began to play with sunlight, mist and shadows giving the painting three-dimensional feel, while the parts of the background Verrocchio did, such as the trees, have more of a static feel. DaVinci used oil paint for his parts of the painting. Oil paints allowed DaVinci to create smoother transitions and gradients between his colors, creating a more realistic look. These smooth transitions can be seen in the shadows and shading of Verrocchio’s parts of the painting, such as the hair of the angel and the shading of Jesus’s body. Something unique DaVinci did was give his angel’s face emotion as well as have the angel be paying attention to the main event of the painting. At the time is was not common for secondary figures to display either of these things. Most secondary figures were depicted like Verrocchio’s angel, staring off bored into the distance. This is just another aspect displaying how ahead of his time DaVinci truly was.

Source: https://www.leonardodavinci.net/the-baptism-of-christ.jsp 

image was found on Wikimedia https://commons.wikimedia.org/wiki/File:Baptism_of_Christ_by_Andrea_del_Verrocchio.jpg

Verrocchio gives up the brush

  In recent times, X-rays have been done on the painting 'The Baptism of Christ' that reveal a completely different outline for the angel that DaVinci painted. This indicates DaVinci followed his own vision rather than his master's from very early on in his career (he was only in his early 20's at this time). Often times people say Davinci's angel stands out from the rest of the painting for it is significantly better, as it is far more realistic and detailed. After seeing DaVinci's detailed and far superior angel in their painting "The Baptism of Christ", Verrocchio became embarrassed and ashamed that his pupil was a better artist than him. It is said that after realizing this he vowed, out of shame, to give up painting for the rest of his life. This rang true, as "The Baptism of Christ" is Verrocchio's last known painting. He continued work as an artist but focused on drawing and sculptures. After this time Verrocchio completed some of his best works such as "The Doubting Thomas" located outside the OrsanMichele in Florence or the "Equestrian statue of Bartolomeo Colleoni" in Venice, Italy.

Sources:  http://www.leonardo-da-vinci.net/baptism-of-christ/

Image was found on Wikipedia https://upload.wikimedia.org/wikipedia/commons/b/b2/Christ_with_St._Thomas_the_Apostle_of_India.jpg

Leonardo da Vinci Incorporates Structural Reciprocity in Other Designs

Leonardo da Vinci demonstrated a thorough understanding of structural reciprocity not just through his arched bridge design, but also through his design of complex geometric structures that could form domes or roofs. He was one of the first scientists in the West to propose complex architectural designs composed of reciprocal structures that extended into three dimensional space. This was revolutionary for the time, as much of Western architecture was predicated upon hierarchical, rather than reciprocal, logic. In the Codex Atlanticus, da Vinci proposed a series of six designs of interconnected, reciprocal geometric shapes. Though the exact date of these designs is not identified, they most likely informed or went hand-in-hand with da Vinci’s work on the arched bridge. Both indicate that da Vinci was thinking about space in innovative ways that no engineers or architects had done before.

Sources:

Pugnale, A., & Sassone, M. (2014). Structural Reciprocity: Critical Overview and Promising Research/Design Issues. Nexus Network Journal, 16(1), 9-35. Retrieved May 16, 2019, from https://link.springer.com/article/10.1007/s00004-014-0174-z

Taddei, M. (2006). [Unique edition of the Codex Atlanticus as a box. Made by Mario Taddei in the 2007]. Retrieved May 16, 2019, from https://commons.wikimedia.org/wiki/File:Mario_Taddei_Unique_edition_of_the_Codex_Atlanticus_-_Codice_Atlantico-www.mariotaddei.net_(27b).jpg

Photo, taken from Wikimedia Commons, is free to use under the Creative Commons Attribution-Share Alike 4.0 License.