687-761 CE (Superpowers)

''Tyrian brought not only peace to the empire but renewed the spirit of cooperation between the Senate and emperors. More than ever, Rome needed this internal unity as she lost the long-held lands of Mesopotamia and Armenia to a powerful new enemy. Although the forces of Islam had become divided, the threat they posed still loomed over Rome. ''

Caesar Valerius (687-738)
Born in a patrician family, Lucius Valerius Messalus was the eventual choice of the Senate as part of their deal with Tyrianus in offering him the titles and powers of a Caesar. Adopted in 673, Valerius was a man in his thirties when chosen to become the next emperor. In many ways, he was the opposite of Cleganus - the emperor who had gone to war against the Senate - as a man with a philosophical distaste for war, taken from his time learning rhetoric and natural philosophy in Alexandria. His temperament and fondness for the painted arts earned him the name Flos, or "the Flower". His opponents in the Senate originally called him a flower derisively but Valerius and his supporters would take the name in stride to emphasize his role as a peacetime leader.

Great Roman inventor
Despite his distaste for war, Valerius understood that Rome would have to defend herself against her enemies and was not naive to the need for a powerful army and navy. The logistics of the Legion were left in the hands of a capable Generalissimus (most general commander of the legions) but its improvement fell under the direct supervision of Valerius. No emperor before him gave as much funding to the Technaeum Armarum et Armatura (Technical School for Arms and Armor) as Valerius, often devoting more than 60 million denarii to the school. With imperial patronage, the Technaeum almost tripled its staff and doubled its student body by 696 as graduates stayed on as doctores ballistarii (artillery technical instructors) instead of joining the Legion.

Among these many teachers, only one is worthy of extended notice. Of course, other doctores made their own contributions but these were only gradual improvements of existing designs, modifying the ridges on the lorica tectata (legionary plate armor) or making a manuballista with a cord of greater tensile strength. The most notable doctor ballistarius was the son of a teacher who had started to work at the Technaeum around 695. Little is known with certainty about this boy's early life except that his father had been taking his child with him to work ever since his mother died. The young Gaius Pistorius Mica supposedly spent his time in the libraries teaching himself from books, including the Sinican Suncius' Ars Bellis and Dionada's On Motion.

Mica properly entered the historical record in 714 upon his enrolment at the Technaeum as a student. Already familiar with the lessons, Mica spent much of his student life conversing with his father's colleagues and watching tests for new artillery pieces. At this time, some of these professors were hiring him to create copies of their designs for distribution to the Generalissimus and other interested parties. Drawing copies was a typical task delegated to students but professors favored Mica for this job as he was not known to make mistakes in his copies and even noticed when there were problems in the originals. The young boy had no artistic talent for these drawings but technical drawings at the time were entirely geometric. Nevertheless, one of his teachers offered to pay for training under a famous artist, so that Mica might produce drawings that had appeal on top of his precision.

Mica's attention to detail and systematic approach to drawing helped him train quickly as an artist. When he graduated from the school in 719, Mica had developed exceptional artistic skills, that would only improve throughout his life, and professors were fighting to have him partnered with them instead of with their colleagues (students who stayed as new doctores were made an apprentice of sorts with senior professors, assisting them with research and teaching before working independently). Already, Mica had suggested changes to the carroballista, noting that its collapsible wooden shell could be replaced with a collapsible wooden skeleton holding up thin leather sheets, if the skeleton were properly designed (something he supplied), and had been one of the minds behind a simple cranequin which reloads a crossbow by cranking a gear that bit into a rack to draw the string.

In 720 CE, Mica made a name for himself beyond Carthage and its Technaeum with his invention of a repeating crossbow that he dubbed a polytrahos (multi-draw bow). His design was simple - a magazine above the stock held ten bolts that would be loaded one-by-one by each forward stroke of a lever. On the backward stroke of the same lever, the string would be pulled back over the short total draw distance. Between stroke cycles, the bolt would release at full draw. The recurve bow that formed the arc of this semi-automatic weapon was of composite material and its string was of sturdy animal fibers which could not be drawn back far but stored a relatively high amount of energy when stretched even a short distance. When fired, the polytrahos had to be positioned on the knee from a half-kneeling position, with one hand on the stock while the other worked the lever.

Wielded by a strong person, a polyhadros could unload its entire magazine within ~15 seconds, as Mica demonstrated to his peers one afternoon in the training field of the Academia Bellica. Onlookers were astounded by the device's performance. The weapon operated by a completely different mechanism from the polybolos, a semi-automatic artillery piece, and was less than half its size anyway, aweing even the most expert observers that day. Within a few weeks, Mica was called to Rome to receive a personal offer of patronage from Caesar Valerius, who had by now heard everything about the young man. His first gift was a large property close to the Technaeum to serve as his private workshop.

Pistorian war machines
As a condition of the emperor's patronage, Mica was tasked with improving the design of his polytrahos for widespread use. As incredible as its function was, the original polytrahos that he demonstrated was a completely impractical weapon. First, there was no means of reloading it on the field once the magazine was depleted, since the magazine was nailed to the stock and had to be sealed to stop bolts from falling out. Second, the power did not match other crossbows of a similar size, although it could still penetrate deep into leather plates and ringmail. Third, firing from the knee would work on the field but was less useful on the battlements of a wall or fort, so other ways to deploy the polytrahos had to be found. Over the next decade, Mica would put a great deal of his time into improving the weapon that made him famous.

Otherwise, Mica was free to pursue whatever work he pleased. This freedom would not go unrewarded for the emperor.

Early war machines
From  721 to  727, he produced only a few devices of note, spending most of his time either working on the polytrahos or building little mechanisms just to test an idea or see where an image led, a formative process in his understanding of machinery. One device that he asked to be shown to the emperor was a  portable bridge which  curled into itself for convenient transport on a cart alongside a legion. His final design unfurled  ~4.73 m  ( 16 Roman ft ) and curled into a cylinder only one and half meters in diameter. This octagonal cylinder sat on its side 1.48 m thick so that the unfurled bridge would be as many meters wide. The bridge was wide enough for two legionaries to march concurrently in formation while metal poles were threaded through its edges to strengthen it enough for carts to cross. Valerius ordered these bridges for cohortes that would leave Roman borders, removing the obstacle of small rivers for the Legion and its supply line.

In early 728, Mica revealed designs for a small assault boat created to ram enemy ships - naming the vessel vespa (wasp) for its particularly potent sting. A single vespa was driven by two paddlewheels each operated one man, using mechanical advantage to increase the speed of his paddling tenfold. The prow was covered by an armored shield, thick enough to shrug off projectiles as large as those of a small mangonel. This shield extended more than halfway back and terminated in a solid metal horn. Once a vespa rammed the enemy, its shield would open to expose a miniature siphon (pressurized hose) for spewing Athenian fire. There was enough of this flammable and waterproof fluid for a short spray that would ensure that the rammed ship would rapidly be engulfed in flames ignited from within the bowels of the ship. Overall, vespae were designed as small and light craft, that could only pierce a hull with their own speed and sharp ram - more importantly, the vespa was a low-cost way to deploy Athenian fire, allowing only two men to destroy an entire enemy ship without help.

An undeniable cleverness could be seen in the design of the vespa, helping Mica's national reputation grow. The two pilots were guided solely by the aid of a polished bronze mirror that doubled as protection for the stubby mast, but the vespa was intended to be aimed at its target before the pilots sat at the pedals. Its shield opened rapidly after pulling the brake - fast enough not to give time for defenders on the deck above to kill the pilots before one of them could light the primer and fire the weapon. Every decareme would have one true vespa and one or two false craft without the fire siphon.

Two years later, Mica demonstrated a ballista that launched lit containers of Athenian fire instead of stones. Ammunition was lit moments before firing and sprayed its fuel upon impact. Although this flame ballista had the advantage of range over the siphon projectors, it lacked the intensity of a continuous stream of fire and required caution as the fuse needed to burn strongly enough not to fizzle out midflight but could not burn too closely to the cords of the ballista. For this reason, the siphon would remain the more common means of deploying Athenian fire, alongside judicious use of fire spitting artillery.

Heavy weaponry
Studying the techniques of ironsmiths in the province of Noricum, Mica had developed by 739 his own process for making an alloy of iron. From the perspective of modern chemistry, his alloy was a high carbon steel forged in a process using crucibles to refine wrought iron. With such common raw material, a forge anywhere in the empire could use his process to create metal that outmatched the famous norica - an early Roman steel that only came from iron smelted from ores mined at particular sites in Noricum. Pistorian steel (norica pistoriana) had superior durability and could hold a far sharper edge than Noric steel, in addition to its capacity for more widespread production.

Mica had a number of plans for his material - ideas that required a more durable and ductile metal than even Noric steel. Earliest of these inventions was a heavy ballista using steel instead of wood as a spring and a composite of animal fibers with bird quills for the cords. Its mechanism echoed the lignaballista in using multiple cords and arcs to fire a single projectile; however, Mica had designed a weapon which did not compromise on maneuverability, particularly as his steel allowed for sturdy moving parts. Another unique feature of his weapon was that its projectile was simply a 37 cm long piece of lead with a shape that "lowers the transference of its momentum (conata) to the air", basically an aerodynamic 57 kg lead shell with a steel tip.

This plumballista was an unprecedented step forward in Roman artillery technology - even a lignaballista could not match its projectile velocity of ~70 m/s. Unlike heavy catapults, a plumballista was light enough to deploy from a carriage pulled by only two horses and to cross Mica's portable bridge (as long as ammunition crossed in a separate cart). Despite its portability, a plumballista caused destruction on a similar scale to the heaviest onagers, with a projectile of smaller weight but greater speed. When deployed by cart, the plumballista fired with such forces that rooting to the ground was required to bolster its frame against its own recoil. Even when gripping the soil, the weapon risked cracking its wooden parts when fired. Two ballistarii were needed to operate a single pumballista - one to crank the loading winch and another to aim and pull the firing lever.

Due to its failings, Mica imagined his new weapon on ships and walls more than on the field, especially considering the length of time required to prepare it for firing. Within a decade, hundreds would be deployed on battlements and the decks of decaremes, where the plumballista completely replaced the traditional heavy ballista. Four of them could be placed on the deck of a deceres in place of two ballista, due to its compactness. Nevertheless, the plumballista would have been most useful on the field where the Legion could deploy one to lay siege to enemy cities and tear holes through entire formations of men. Mica would spend a great deal of time finding a compromise that would make his weapon more feasible as a mobile artillery piece.

First, he resolved most of the problems by removing the ability for the plumballista to swivel from right to left. Firing along the axis of its own motion, the weapon would only roll backward when fired instead of overstressing the frame or unbalancing the weapon. However, Mica felt inspired to design an entirely new frame for the weapon, a notion that would give birth to his most versatile war machine after nearly a decade of meticulous work.

Steel tortoise
Designs for this latest machine were sent in 750 to the emperor - delivered under the title of testuda invicta (unconquerable tortoise). Enveloping the plumballista in a conical steel shell, Mica had created a moving, armored artillery piece that could charge under its own power into battle, tearing down walls and men alike. Inside, five men were sheltered. When in motion, one man acted in turn as the pilot, watching through thin glass slits and directing the actions of his companions. The others worked in pairs on either the left or right set of wheels, pedalling forward or backward at different rates when directed by the pilot. With the mechanical advantage afforded to the working legionaries, the testuda plodded along at the pace of marching troops but would still leave its men exhausted after less than a half hour of travel. For this reason, Mica advised a legion to pull a testuda by mule when not in battle and to allow its pilots to ride within to stay rested for the intensity of combat.

However, a testuda left little room within for its occupants. Its middle axis was dominated by the plumballista which could only angle vertically, after the lessons Mica had learned with the field artillery piece. Just above the main weapon were two polytrahos scaled upward to increase their power and magazine capacity. Most of each turret lay safely within the testuda shell, swiveling freely about where their long snouts - extending several inches ahead of their respective arcs - attached firmly to the vehicle wall. In battle, two of the pilots manned these turrets while two others constantly passed them magazines on wall racks all around. The last man both fired the plumballista and reloaded it with the assistance of the two ammo feeders, cranking its winch himself.

Before battle, other legionaries would run the pedals for as much time as they had in order to charge the flywheel for each pair of wheels. This storage device had been designed a decade and half earlier by Mica, requiring a few modifications to avoid losing most of its energy to the sudden bumps and shocks that were inevitable when riding inside a testuda. Enough energy was stored on a full charge of the flywheels to ease the legwork of the men driving the machine but not enough to move it fast on their own. Each flywheel consisted of two 12 kg steel balls on opposite ends of a 0.42 m steel bar that rotates about its center, placed at the same height as the wheels and able to drive its respective wheels by engaging a small lever in the cabin. The property of the flywheel that made its use here possible was the ability to slowly bleed off mechanical energy to the wheels.

Tactics for using a testuda in a siege and in open battle were detailed in a short booklet that Mica included with his designs. A testuda needed decent infantry support on a field but returned the favor with its devastating effectiveness against cavalry and its invulnerability to archers. Since its polytrahoi could maintain a firing rate of one shot per second, massed infantry were also quite vulnerable to a testuda, although they could disable one once close enough and a limited ammo capacity restricted a testuda to only 1,000 bolts from its polytrahoi and 10 shells from its plumballista. However, Mica noted the potential to crush enemy morale with the sight of a seemingly invulnerable machine that would be killing almost one man every second for the first quarter of an hour of battle - also mentioning the bonus to the morale of one's own troops by fighting alongside such a monstrosity.

On open field, the conical shell of a testuda towered almost eight feet above a legionary. Its bulge at the widest point extended out far enough to allow two men to lie down inside its belly and fully extend their arms and legs (nearly 16 feet wide). For armor, a testuda had almost five tonnes of Pistorian steel wrapped around its cone, offering an inch thick wall to the harsh world. The wooden frame added another two tonnes, for a total of nine tonnes when full of ammunition and men. Every attempt was made by Mica to conserve weight, since the men inside needed to move everything by their own strength.

Mica boasted that a testuda was the only siege engine that a legion would ever need. No wall, or at least no gate, could stand against its powerful plumballista and an army would feel half its actual size in the face of its turrets. Nevertheless, he advised the emperor to provide one to every cohort - ten for each legion - so that the armies of Rome might be invincible. Instead, he heard that only one would be made in Carthage, under Mica's supervision, before the decision for mass production would be made. The new emperor was less enthused by Mica than Valerius but he would not miss an opportunity such as was being offered.

Later war machines
As Mica entered his twilight years, his prolific mind did not slow, although the ambition of his projects was tempered. Five years before he delivered the plans for the testuda, Mica sent the emperor his final designs for the polytrahos. Since the first repeating crossbows had been made, the auxiliaries of Africa Proconsularis had been equipped with them. Without a doubt, the simple to use but effective weapon was suited to the amateur troops who guarded the borders and towns of the province. Criminals were loathe to confront a town guard when he could easily loose enough arrows to turn him into a pincushion before he drew a blade. For its success, the polytrahos had become the standard armament for auxiliaries by 754.

In particular, the polytrahos is seen as the weapon that tamed the Wild North of Magna Germania. These were sold freely only in Germany, where merchants and homestead owners could use them to defend themselves against the wild men descended from the original residents of the land. Suddenly, one man could hold off an entire band of men, even from his horse, where before only a large trade caravan could bring along a polybolos cart to protect its goods while citizens living on farms could only rely on a polybolos wherever they stationed one as a turret, giving raiders the opportunity to avoid their primary means of defense.

For town guards, Mica designed a saddle-mounted polytrahos that restricted the horse to a slow trot but turned the rider into a formidable keeper of the peace. Sitting with his weapon in front, these auxiliaries could patrol at leisure without worrying about having to pull their weapon off their back at the first sign of trouble. Sending even one guard on horse with a polytrahos would do as much as sending ten archers, meaning the auxiliary guard vastly improved in its efficiency.

Dozens of other turrets, each of a different size or ammunition capacity, were designed for future needs, as Mica did not trust anyone to accomodate his design to suit a new problem. Few of these would ever see the light of day. However, the most useful of them was a large turret intended to replace the polybolos on the battlements of Roman walls. A holster for magazines gave one defender the ability to loose nearly five hundred arrows without assistance or preparation, unlike the polybolos which needed one man to crank and another to feed ammunition. This heavy polytrahos would become a reliable ally for auxiliaries on defending the borders of the Roman Empire, turning a single soldier into an entire battery of archers.

Unused war machines
For every siege engine that the emperor accepted from Mica, there were two or even three that were rejected as impractical or even impossible. A long list of these inventions is difficult since there are no single terms for them, obscure as they still are. However, an attempt can be made to describe a few of these strange devices. The majority of these devices can be found in the writings of the great inventor or in fragments of letters that he sent to Rome.

Sketches of a diving suit, a diving bell, and other small water craft were sent to the emperor alongside designs for the vespa. For fighting one of the Caliphates, Mica suggested a procedure for diverting the course of the Euphrates and the Tigris into the Oceanus Hyrcanianus (Caspian Sea) to permanently wipe out the center of Persian civilization. Similarly, he proposed a canal that crossed the peninsula separating the Mare Rubricum from the Mediterranean. This canal would link the two largest high fleets of the Roman Navy and would make the Red Sea accessible to ships built from the great shipyards of Carthage.

Following the lead of Archimedes, he created versatile cranes for lifting ships out of the water during a naval siege as well as a handheld version of the siphon for spraying Athenian fire. There were also sketches of a carriage housing a mobile forge for replacing weapons on the field and for filling ships with Athenian fire before igniting them in proximity to a formation of ships. Aside from these unique devices, there were also numerous designs for different versions of those war machines that were in the end accepted, where these variations could be small or great in scale.

Electrical technology
Perhaps the primary object of Mica's fascination was the ampera (electrochemical cell) that had been a mere curiosity of the philosophers for nearly a century now. A few decades before Mica graduated from the Technaeum, one philosopher in Athens had assembled a voltaic pile consisting of nearly a thousand copper and zinc pairs. His battery got used to create some of the first arc discharges in front of an audience of his peers, stunning them with the ferocity of its arcae (electrical arcs). This battery was overshadowed by the Magna Ampera Alexandriae (Great Pile of Alexandria) that brought nobles and scholars to that city to witness its power. Assembled in 687, the Alexandrian battery was the first trough battery, solving the ongoing issue of electrolyte leakage from the vinegar-soaked cloth in voltaic piles.

By now, scholars knew that the copper node (cathode) needed to be connected to the zinc node (anode) by another metal for sparks to be generated. Indeed, they had improved the process by wrapping a thin strip of copper around the nodes then taking each strip attached to the nodes and touching them together to generate sparks. This separation of the sparks from the nodes of the ampera relegated the metallic degradation to an external metal which could be more easily replaced than the nodes, a major problem as voltages increased. In the decade leading up to the two great batteries, scholars had taken to wrapping the copper wires around gold rods that they would touch together to generate their sparks. This method made for a grand display the first time the Athenians demonstrated their great battery.

Alexandrian scholars working with their great battery noticed violent bubbling when the gold rods were dipped together into water. One philosopher was singed upon removing the rods and producing a brief spark - the air above the water exploded in a small burst that stretched in a line up from the bath of water. The violence of this event prompted further research, with the scholar who witnessed the event believing that he had somehow created lightning on a scale seen in nature. Since they were now trying to create true lightning, the experiments were moved to a square away from the Musaeum.

Although the explosion easily got repeated, it was weaker out in the open and people watching from a far during the nighttime could say with confidence that it resembled lightning less than an arca. They viewed the result more as a "sudden fire" that had snuffed itself out almost as quickly as it appeared, almost as though the air were filled with petroleum. When Pistronius Mica was shown the sudden fire on a visit, he told the scholars that there was obviously something floating away from the water "like bubbles rising through the air" and the spark somehow ignited these bubbles, an inference that he corroborated by having them light a puddle of naphta using an electrical discharge (showing that electrical arcs could ignite flammable materials).

After the experience, Mica created a new great battery at his workshop in Carthage to pursue his own experiments. He used glass vessels to catch the bubbles then hold them in by plugging the container. Once he had a vessel with the bubbles, he put a torch over the opening then released the plug, watching the flames grow violently as he expected. He sent word of his discovery of the bubbles of wispy oil and his experimental method to the scholars at the Musaeum.

Discovery of electromagnetism
A year after Mica began experiments with his battery in 734, Mica's assistant noticed that the compass in his workshop changed directions every time an electrical arc was generated. After confirming these observations, Mica tried varying sizes of amperae to see how the effect varied, finding that it dwindled down to the barest of nudges at low number of copper-zinc pairs. He also tried different compass positions relative to the discharges and ran a few tests without any discharges, instead using a single copper wire between the two nodes of his strongest battery. Within a few months, he confidently wrote in his journal that whatever caused electrical sparks must be present even when no sparks were visible and that this substance somehow affected magnetic materials such as the needle of a compass. This principle was the first step toward electromagnetism - the theory of how magnetism and electricity are fundamentally connected.

After two years trying to study "movement by electricity", Mica finally found something worth sharing with his colleagues at the Musaeum: a metal rod rotated continuously if hung above a magnet and connected by gentle touch to a battery. His apparatus was the first homopolar motor, a piece of metal rotating inside a unidirectional magnetic field due to an internal current. His two discoveries about electricity finally made something of the peculiar phenomenon, where before it was only a curiosity.

Mica performed dozens of other experiments on magnets and electricity throughout his life. He found that two live wires exerted a mutual force and that the direction of this action changed based on the orientation of the wires. Finding that amperae composed of other metals also displayed the same phenomenon, Mica argued that orientation was important to every battery. However, he did not use this as evidence for the direction of travel of the "exhalations" believed by most philosophers to produce sparks, as he staunchly withheld judgement on the origin of electrical sparks. As far as he was concerned, something was active in wires when connected in a circuit and whatever this was it affected magnets. Even knowing this, he knew not what this thing was.

What mattered was that Mica had found a way to detect electricity - a method that even measured its strength to a degree. Other philosophers would create lighter compass needles to increase the sensitivity of this rudimentary detector. They were also intrigued by Mica's motor, despite how useless such rotation was in its present form.

Practical uses of electricity
Other applications of electricity than the motor were found by Mica. However, every one of these uses would prove impractical on a larger scale for one reason or another. Early on, he noted that a person could be interposed between two points along a wire, causing tremendous pain and ghastly burns on the victim's skin. When the person's body formed part of this connection, death was found to result when the battery was strong (Mica performed his first tests at over 300 V). A lower voltage run across an arm or hand was recommended to the Legion for torturing enemies of Rome.

A few years later, he pursued reports that a wire would start to glow after a long period of connection to amperae. Using the metal of his own design, he connected a variety of shapes to his battery, finding that thinner material became hot and red faster than thick material. In this direction, he forged a thin strip of steel that would heat to a glow within seconds, noting that he could write at night by the light shining from the charged metal. Unfortunately, the glowing strip burned out in a short time.

In 751, he strung 24 wires between two rooms in his workshop, each terminating in a small break where sparks would fly whenever a current passed through that wire. Nodes on the other ends could be touched by a gold rod to complete the circuit, allowing Mica to write out sentences to a person in the other room by touching the wire for each letter in the order of the desired words. Years earlier, Mica tested the limits of copper wire, stringing some across his workshop and the nearby houses, with the consent of his neighbors. From these tests, he learned that sending messages between cities was impossible.

Overall, Mica made very little of electricity and did not spend near as much time with it as with his mechanical inventions. Still, he pioneered many firsts with electricity, inspiring proper applications of electrical technology in the future.

Roman industry
First and foremost, Pistorius Mica was a military engineer employed by a national academy for weapons of war. Nevertheless, his curiosity and the freedom allowed in his work left some spare time for him to pursue non-violent applications of machinery.

Most of his civilian inventions were commissioned by merchants working out of the Grand Harbor of Carthage. A number of them were merely improvements on existing devices. For example, Mica created a water-powered paper mill, improving upon the paper mill invented in Alexandria around 650 by allowing for the continuous forming of paper sheets using rollers. Machinery for pulp mills, grain mills, stamp mills, and sawmills were invented by Mica from 730 to 751, before he left Carthage on a series of trips for the sake of his testuda. Meanwhile, he also worked with shipwrights in the development of the double hull for ships, although its invention is only partially attributable to Mica.

Wind-powered mill
His greatest civilian invention during this twenty year period was the windmill, using the windwheel designed several centuries earlier by Hero of Alexandria (10-70 CE). His original windmill had a similar appearance to the waterwheel except wooden panes were replaced with a light fabric on a wooden skeleton and a wooden barrier blocked the wind blowing through one half of the windwheel, replicating the way a waterwheel is only half-submerged into flowing water.

Several windwheels were put on the roof of the Grand Harbor for powering the cranes used to transport cargo throughout the docks, lightening the load for the person operated those cranes. Indeed, the rooftop windwheel would become a popular device for driving low power machines in coastal cities. Due to the axial symmetry of how windwheels were connected to the machines they powered, the "well" in which the windwheel sat on a roof could be rotated to catch a better wind. These rooftop mills did not take long to grow in popularity among artisans, especially in places where water was not as abundant as Italy or Germany.

Windpower may not have been as strong as waterpower could be and energy could not be stored for later use, but it was far more readily accessible given the dwindling number of water resources in the empire. In fact, the Roman Empire was close to reaching its peak capacity for water power in some of its provinces, capping its industrial growth. In Rome itself, industries had access to the equivalent of ~1 billion kWh of mechanical energy from its aqueducts, using it to drive watermills for grinding grain, making paper, sawing wood, polishing lenses, and billowing forges within the city. Centuries of integrating machinery and aqueducts into workshops in Rome had led to this unprecedented access to non-electrical energy. For this city of 1.3 million, an average citizen had ~769 kWh of energy, but in practice most of this energy went to workshops and the homes of nobles.

Although the rooftop mill would not become popular in Rome itself, the nearby town of Portus, also known as Ostia, benefitted a great deal from its use, nearly doubling its access to energy over the next few decades. Other port towns experienced a similar industrial growth as workshops throughout the Roman world commissioned their own rooftop mills. Inspired by his windwheels, Mica invented a better anemoscope that indicated wind speed by its rate of rotation. He built several of these anemometers for the Grand Harbor in 744, giving a reliable means of knowing the speed of the wind before setting sail. Other more open air ports would find his anemometer more convenient to display to people on the docks.

Roman industrial capacity
There is no comparison in any other part of the world to the industrial capacity of the Imperium Romanum during this time. Centuries of peace within most of its provinces had permitted sophisticated applications of machinery alongside the existing infrastructure of aqueducts. However, an industrial revolution of sorts can be considered to have started near the end of the 5th century, when the first urban watermills were built to operate from energy supplied by aqueducts. Concrete dams would be built near the starting location of aqueducts to raise water to a higher starting elevation, allowing watermills along the length of an aqueduct to draw power while leaving a great deal of energy for when the water reached a city.

By the 8th century, this process had reached a peak in Italian cities, tapping as much of the water supply for power as was practical. Geologists at the time had determined that Italy could draw no more water for its cities and farms given the availability of water on the peninsula. At this point, Italian cities had daily access to almost 50 amphorae (343 gallons) per citizen during the Summer while farmers used a separate supply of water for crop irrigation. In Greater Germany, access to waterpower was still growing, bolstered by extensive river networks in the region. Overall, the empire had an industrial output that stood midway between a pre-industrial and an industrial civilization, exceeding any of its contemporaries by orders of magnitude.

Textile industry
Around the turn of the last century, a weaving machine powered by pedals was introduced to Syria from the Islamic world. Replacement of hand looms with the vertical pedal loom was slow but Mica heard about it from colleagues who came from the eastern provinces. In 739, he improved upon the design by use water-power in place of a pedals for operating the heddles. Some weavers in Egypt would further improve upon the water-powered loom around 780 by replacing the warp-weighted vertical loom that had been used for centuries with an easier to use horizontal loom.

A few years later, a weaving guild in Carthage commissioned Mica to create a device for spinning thread into yarn, freeing laborers for more intricate work. His piece was a spinning wheel that could be powered by either water or a treadle. The former could be powerful enough to produce the high quality yarn required for weaving. This device would be steadily improved by other more devoted craftsman than Mica, until around 840 when hand spinning went out of practice for Roman citizens.

Agricultural tools
Agriculture was an immense industry in Africa Proconsularis, where a handful of aristocrats owned massive latifundia (landed estates) where slaves farmed crops for shipment to Italy and Greece. Besides Egypt and Germany, the lands around Carthage were the primary source of food for the empire. Hearing of the prowess of Mica with machines and being dependent for centuries on the mechanical reaper for harvesting crops, some of these nobles approached the great inventor to improve the reaper.

Visiting the countryside for a few seasons, Mica compiled an ordered list of steps in the production process of their farms and detailed existing tools and techniques for each stage. However, he was forced to leave Carthage for a decade to lobby for his testuda and supervise its construction in Greater Germany. Upon his return, Mica had a number of ideas for the latifundia of his home province - ideas that he would show his potential patrons in 765.

First, he noticed that slaves often had to carry large bags themselves across short distances on the estates and that slaves were limited in how much they could carry, requiring multiple trips or slaves for many tasks. In response, Mica repurposed the Greek pabillus (one-wheeled cart), used on some construction sites, for carrying large loads over short distances. Indeed, he designed such a large number of these wheelbarrows that he recommended that the latifundia keep dozens of them for different tasks.

Second, he modified the heavy mouldboard plough by making the mouldboard removable so that the soil could be tilled in one direction for one furrow then the opposite direction for the other furrow, for continuous plowing of the field. This new plough would also prevent the build-up of soil into ridges that produced the characteristic topography of agricultural land.

Finally, he suggested a three-field crop rotation where one field would remain fallow out of three, instead of the commonly practiced two-field crop rotation where half the arable land of an estate was not used for crops. His recommendation primarily added a year in the crop cycle where a field would be used for legumes such as peas or cabbages. However, Mica cannot be given credit for this idea as he had learned of the replenishing power of legumes for a field when traveling in Italy, where a similar technique was already employed by farmers.

Printing press
After returning to his workshop in 762, Mica effectively retired from working for the Legion. His final designs for a polytrahos were in the hands of other capable military engineers and several of his testudae had been constructed, leaving behind enough experts to carry on their production. Back home, he got to implementing some ideas that came to him during his voyages throughout the Mediterranean. First among these ideas was a screw press that forced ink into paper, leaving an imprint of an image. This image could be a series of letters arranged into the page of a codex, allowing the repeated printing of a single page onto pieces of paper. Once arranged, a page could be printed in the seconds it took to apply the ink and crank the screw press.

His design for a printing press was inspired by a visit to the imperial mints in the capital - the only location with the authority to create coins. Based on their operation, he designed a machine that instead of punchcutting coins would punchcut moulds as templates for casting metallic types of letters. Letters were arranged on a plate for pressing. This movable type printing press was used to create dozens of copies of Mica's favorite book - On Motion by Dionada - in 763 with the help of a dozen assistants for arranging the types. Over the next few years, Mica found a better metal alloy for casting durable types and invented a water-powered printing press machine that could alternate pressing and releasing by changing a single gear.

Pistorian presses were created for the Technaeum, printing copies of the Commentarii de Bello Gallico by Julius Caesar, a text that all Roman officers graduating from the Academia Bellica were required to know. With eight printing presses, the academy had printed thousands of copies of the Commentaries by 770 and some merchants were bringing the idea to Italy and Egypt. By 800 CE, there were nearly a thousand printing presses throughout the empire, each printing over 3,000 pages every day. Printing became just another Roman industry but it would be one that would revolutionize Roman society by bringing literature into the hands of the common people - a similar change had never been wrought by the production of any other good.

Pistorian physics
More than anything else, Mica contributed to the history of science and engineering with his theories and techniques for studying nature. Teaching himself by reading Dionada at a young age, Mica stuck his whole life to the basic principle of Atomism - that every object was composed of indivisibles and the motion of anything could be studied by the linear motion of its atomic parts. With these beliefs, he led a revival of Atomism in the empire, as its ideas permeated all of his writing. No one could read first hand about the discoveries of the great Pistorius Mica without seeing them through the lens of Atomism.

Later in his life, Mica published a treatise that summarized his understanding of mechanics through Atomism, presenting what he termed the First Principles of Motion: From these laws, Mica went on to describe how conata (efforts, or in other words, momentum) was exchanged, expanding the theories of Dionada beyond just collision. His theory is that the actus (action) of one atom upon another is required to change the motus rectus (rectilinear motion) of an atom, as he saw motion in a straight line as the natural state of every atom. There were two types of action in Mica's physics: collision and action at a distance. The latter replaced Aristotle's teleological explanation of gravity and buoyancy through his concepts of natural motion and the natural places of the elements. These notions had been on shaky foundations ever since material philosophers such as Balerios added elements to the original five.
 * 1) An atom travels straight unless it is acted upon by another atom.
 * 2) The action of one atom upon another involves no loss of momentum from any atom.

Modestly, Mi ca professed that he could not say how but he could plainly see that it is  necessary that some atoms can push or pull other atoms without collision. Action at a distance developed from Dionada's concept of connection, which he described as a tendency for atoms to attract when moved away from their natural arrangements and used to explain gravity and elasticity. The difference between action at a distance and connection was that the former manifested as a change in motion along a line joining the interacting atoms instead of in the direction that brings those atoms back to their "natural arrangement". Indeed, Mica did away with natural arrangements as much as he threw out Aristotle's natural places.

Several observations further developed Mica's concept of action at a distance, especially as it manifested as gravity. First, he pointed out that lighter objects fall no faster than heavier objects. His theory of gravity required that its action on heavy bodies was greater than its action on lighter bodies but he observed that heavier bodies were harder to move by the same proportion so the result was an identical change in motion under gravity for all bodies. Second, he observed that dropping an artillery shell from the mast of ship did not involve the ship leaving the shell behind, as Aristotle believed. Instead, the shell retained the motion of the ship even after no longer being in contact with the ship as it fell. For this reason, Mica believed that a person below deck on a ship, that could sail through the sea without rocking, would be unable to say whether or not the ship was moving, since objects would fall or follow trajectories no differently on a stationary than on a smoothly sailing ship.

Third, he followed Dionada in arguing that the Earth, as the heaviest aggregate of atoms in nature, pulled on the planets and sun in the same manner that it pulled on ordinary bodies through gravity. His seminal treatise Prima Principia Kineses became the first widely received natural philosophy text to say that the forces in the heavens and force of gravity were the same force. It also contained a large number of geometrical problems for calculating the force of gravity whose methods for being solved are not far from the method of integration, as they follow the geometrical method of exhaustion pioneered by Archimedes.

Fourth, he discovered by careful measurement that a distance fallen by a body was proportional to the square of its time spent falling, by a numerical factor that he determined as precisely as possible by hundreds of experiments. For his measurements, he had to invent a new tool for measuring time on a small scale. Copying the water clock, Mica filled a sealed glass container with sand so that once turned over sand would drip into the adjacent vessel at an unchanging rate. In order to save time, he made the glass vessel symmetrical so that the chamber into which the sand dripped was identical to the chamber in which it started. This simple tool was the first hourglass, a precise and reliable way of measuring the passage of time.

For precision, Mica had his hourglasses marked with lines from the top down to represent the timing of his resting pulse. For most of his life, Pistorius used his pulse to time his experiments but he knew his pulse to change with his mood so in 727 he invented the hourglass to record the timing of his pulse and have a reliable measuring device for time. Afterward, he used this first hourglass to mark other hourglasses so that he could measure longer spans of time. A number of his experiments would not have been possible without the hourglass, especially since many of his experiments were performed on ships.

His reasoning for using sand instead of water as in a water clock was that the granular size of sand particles allowed for greater precision in his measurements and the dryness of sand prevented the condensation problems that ruined the measurements of water clocks. Furthermore, a sealed hourglass was vastly more portable than any water clock, making it useful at sea. A gradual dissemination of the hourglass from Carthage and Alexandria persisted for the next century.

As much as he explained action at a distance, Mica contributed immensely to the Roman understanding of collisions and simple machinery, drawing on what he had learned in the formative period of his career. He corrected the ancient Hero of Alexandria on the mechanical advantage of an inclined plane, using an argument involving a string of beads around two inclined planes. He was also the first to note that there was a unique ratio of the semichordis (sine) to radius (cosine) for every angle, identifying this ratio with the slope of an inclined plane for the purpose of calculating actions (forces). Furthermore, he observed that this ratio at the angle of repose of an object on an inclined plane was approximately equal to the ratio of the action of friction to the action of gravity on the object as it remained stationary on the incline.

With his Principia, Pistorius Mica is regarded as the father of a new mechanics, one that replaces the dogmatic Aristotelianism and intimately incorporates the physical principles of geometers, who were the driving force behind Roman engineering. His work on a new mechanics earned it the names Pistorian physics and Pistorian mechanics.

Beachhead in Somalia
After the First Fitna (Islamic Civil War), the two caliphates settled into a mutual peace promulgated by their leaders Husayn ibn Ali and Ibrahim ibn Hakkam. Even after the death of Husayn in 693, peace persisted in the Islamic world as each caliphate focused its efforts on other troubles. For his part, Ibrahim felt it his duty to spread Islam to the people of the Roman Empire, no matter how effectively they had existed the forces of Islam in the past.

For this purpose, Ibrahim sent an army by sea in 688 to take the city-states of Somalia as a beachhead for his Caliphate. With only a few merchant fleets and city guards for defense, the desired ports fell within a few months of the first landing. In response, the Legion was forced to bring ten legions to bear against the 90,000 Muslim soldiers brought from Arabia. Fortunately, the last forty years of peace had given the empire time to recover from its tremendous losses against Caliph Umar. There were as many as 14 out of 26 legions in the eastern provinces, allowing Rome to draw only from its regional defenses for this war.

Unfortunately, the dignitatum arabicum did not learn of this invasion beforehand, as his predecessor had managed before Umar invaded Nubia. Without a warning, the legions did not arrive in time to assist the provincial auxiliaries defending the border with Somalia, allowing the Arabs to cross the Limes Somalianus before they even reached Ethiopia. Nevertheless, the legions were able to beat them to the city of Aksum, in time to fortify their position.

As a result, the war devolved into a year long siege of the provincial capital. The legatus refused to give up his strong position behind both city walls, hasty ditches, and giant caltrops, while the Arabian general refused to waste men on an assault. In the third month, the Arabs learned that they needed to demolish the aqueducts leading into the city, discovering in the process that food was being covertly sent to Aksum through its water supply. On the eleventh month, reinforcements finally arrived from Dacia with the Generalissimus at their helm. Arriving in the night, he hastily began a circumvallation of the besieging forces, getting enough defenses assembled overnight to discourage an immediate counterattack.

A few days later, the Islamic forces decided to roll the dice with a direct assault on the fortified city of Aksum. Beginning early in the morning, they had enough time, before the surrounding legions awoke, to break through the city gates. However, in the close confines of the city streets, the Arabs were overwhelmed by the superior infantry tactics, training, and armor of the legionaries. Unable to escape, their general was captured to be made an example to future generals and caliphs by torture in Rome before being returned to Mecca as a mere shell of his former self. His brutal treatment would give pause to future invasions.

However, the Arabian foothold in Somalia had allowed them to replace several merchant princes with Muslims who were more sympathetic to the spread of Islam than previous leaders. In 710, the federation of Somali cities splintered through a religious war between Christians, polytheists, and Muslims, each group seeking control of various ports. With Roman support, the Christian princes were victorious a few years later but there was no way to remove the Islamic presence without purging each city council.

Caesar Glaucinus (738-761)
From a prominent patrician family like his predecessor, Lucius Aemilius Glaucinus was adopted by Valerius midway through his reign. He was more experienced in war than Valerius, serving a few years as his Generalissimus during a brief conflict with the Fatimid Caliphate. When in power, his goal was to weaken the Germanic kingdoms to the north of his empire, leading to a level of war in Europe unseen since the days before the conquest of Greater Germany.

Maya Conglomerate
Pakal the Great's conquests were not yet complete by the turn of the century, and his armies continued to advanced southward all the way up to 714. By that point they had reached the Isthmus of Pakal, the thinnest point of land leading up to South Columbia. At this point, a wall 20 meters high and 9 meters thick was built to block the land off entirely. This wall was completed in 716 CE, only 4 years after advanced scouts sent into the jungle further south failed to return.

Still, the Mayans had already conquered a great deal of land over the past 50 years and had yet to fully consolidate this territory. Estimates, done by later historians, calculated that around 4 million natives were killed over the course of the wars, or in other words, only 5% or so of the previous population remained in the area. This number was further reduced by disease and the taking of slaves so that by 730 all Tribal States were officially allowed into the Council as Mayan States, meaning they were now almost entirely populated by ethnic Mayans.

With all their troubles in the South taken care of, and no danger from an attack on their enormous coastal borders, the Mayans now put their entire focus towards the North and the integration of the rest of the Mexica States. Whilst those regions had most of the infrastructure of Mayan States, only about four had been changed and several dozen still remained. This issue was not a major one within the Conglomerate, and so it was merely done gradually over the course of centuries. For the time being, the government's main focus was the increasingly violent Native Tribes and as Pakal II died in 727, resolving this was left up to his successors.