Title: Leonardo da Vinci
Content:  auction. Revered for his technological ingenuity, he conceptualized flying machines, a type of armored fighting vehicle, concentrated solar power, an adding machine, and the double hull. Relatively few of his designs were constructed or even feasible during his lifetime, as the modern scientific approaches to metallurgy and engineering were only in their infancy during the Renaissance. Some of his smaller inventions, however, entered the world of manufacturing unheralded, such as an automated bobbin winder and a machine for testing the tensile strength of wire. He made substantial discoveries in anatomy, civil engineering, hydrodynamics, geology, optics, and tribology, but he did not publish his findings and they had little to no direct influence on subsequent science.
Title: Science and inventions of Leonardo da Vinci
Content:  smaller inventions entered the world of manufacturing unheralded. As an engineer, Leonardo conceived ideas vastly ahead of his own time, conceptually inventing the parachute, the helicopter, an armored fighting vehicle, the use of concentrated solar power, a calculator, a rudimentary theory of plate tectonics and the double hull. In practice, he greatly advanced the state of knowledge in the fields of anatomy, astronomy, civil engineering, optics, and the study of water (hydrodynamics). One of Leonardo's drawings, the Vitruvian Man, is a study of the proportions of the human body, linking art and science in a single work that has come to represent the concept of macrocosm and microcosm in Renaissance humanism.
Title: Leonardo da Vinci
Content:  1499, he found employment as an engineer and devised a system of moveable barricades to protect the city from attack. In 1502, he created a scheme for diverting the flow of the Arno river, a project on which Niccolò Machiavelli also worked. He continued to contemplate the canalization of Lombardy's plains while in Louis XII's company and of the Loire and its tributaries in the company of Francis I. Leonardo's journals include a vast number of inventions, both practical and impractical. They include musical instruments, a mechanical knight, hydraulic pumps, reversible crank mechanisms, finned mortar shells, and a steam cannon.  Leonardo was fascinated by the phenomenon of flight for much of his life, producing many studies, 
Title: Science and inventions of Leonardo da Vinci
Content:  Leonardo da Vinci (1452–1519) was an Italian polymath, regarded as the epitome of the "Renaissance Man", displaying skills in numerous diverse areas of study. Whilst most famous for his paintings such as the Mona Lisa and the Last Supper, Leonardo is also renowned in the fields of civil engineering, chemistry, geology, geometry, hydrodynamics, mathematics, mechanical engineering, optics, physics, pyrotechnics, and zoology. While the full extent of his scientific studies has only become recognized in the last 150 years, during his lifetime he was employed for his engineering and skill of invention. Many of his designs, such as the movable dikes to protect Venice from invasion, proved too costly or impractical. Some of 
Title: Science and inventions of Leonardo da Vinci
Content:  The viola organista was an experimental musical instrument invented by Leonardo da Vinci. It was the first bowed keyboard instrument (of which any record has survived) ever to be devised. Leonardo's original idea, as preserved in his notebooks of 1488–1489 and in the drawings in the Codex Atlanticus, was to use one or more wheels, continuously rotating, each of which pulled a looping bow, rather like a fanbelt in an automobile engine, and perpendicular to the instrument's strings.
Title: Science and inventions of Leonardo da Vinci
Content:  Vasari in The Lives says of Leonardo: "He made designs for mills, fulling machines and engines that could be driven by water-power... In addition he used to make models and plans showing how to excavate and tunnel through mountains without difficulty, so as to pass from one level to another; and he demonstrated how to lift and draw great weights by means of levers, hoists and winches, and ways of cleansing harbours and using pumps to suck up water from great depths."
Title: Science and inventions of Leonardo da Vinci
Content:  With the same rational and analytical approach that he used in anatomic studies, Leonardo faced the study and design of a bewildering number of machines and devices. He drew their "anatomy" with unparalleled mastery, producing the first form of the modern technical drawing, include a perfected "exploded view" technique, to represent internal components. Those studies and projects have been collected in his codices and fill more than 5,000 pages. Leonardo was a master of mechanical principles. He utilized leverage and cantilevering, pulleys, cranks, gears, including angle gears and rack and pinion gears; parallel linkage, lubrication systems and bearings. He understood the principles governing momentum, centripetal force, friction and the aerofoil and applied these to his inventions. His scientific studies remained unpublished with, for example, his manuscripts describing the 
Title: Science and inventions of Leonardo da Vinci
Content:  governing friction predating the introduction of Amontons' laws of friction by 150 years. It is impossible to say with any certainty how many or even which of his inventions passed into general and practical use, and thereby had impact over the lives of many people. Among those inventions that are credited with passing into general practical use are the strut bridge, the automated bobbin winder, the rolling mill, the machine for testing the tensile strength of wire and the lens-grinding machine pictured at right. In the lens-grinding machine, the hand rotation of the grinding wheel operates an angle-gear, which rotates a shaft, turning a geared dish in which sits the glass or crystal to be ground. A single action rotates both surfaces at a fixed speed ratio determined 
Title: Science and inventions of Leonardo da Vinci
Content:  Leonardo's study of the motion of water led him to design machinery that utilized its force. Much of his work on hydraulics was for Ludovico il Moro. Leonardo wrote to Ludovico describing his skills and what he could build: "...very light and strong bridges that can easily be carried, with which to pursue, and sometimes flee from, the enemy; and others safe and indestructible by fire or assault, easy and convenient to transport and place into position." Among his projects in Florence was one to divert the course of the Arno, in order to flood Pisa. Fortunately, this was too costly to be carried out. He also surveyed Venice and came up with a plan to create a movable dyke for the city's protection against invaders. In 1502, Leonardo 
Title: Leonardo da Vinci
Content:  During his lifetime, Leonardo was also valued as an engineer. With the same rational and analytical approach that moved him to represent the human body and to investigate anatomy, Leonardo studied and designed many machines and devices. He drew their “anatomy” with unparalleled mastery, producing the first form of the modern technical drawing, including a perfected "exploded view" technique, to represent internal components. Those studies and projects collected in his codices fill more than 5,000 pages. In a letter of 1482 to the lord of Milan Ludovico il Moro, he wrote that he could create all sorts of machines both for the protection of a city and for siege. When he fled from Milan to Venice 

Question: what are some inventions that leonardo da vinci invented?
Answer: Double hull.