Inventors and Inventions from the 1500's - the Sixteenth Century

[Dept of PMM Artists & things]

COMPOUND MICROSCOPE Zacharias Janssen was a Dutch lens-maker who invented the first compound microscope in 1595 (a compound microscope is one which has more than one lens). His microscope consisted of two tudes that slid within one another, and had a lens at each end. The microscope was focused by sliding the tubes. The lens in the eyepiece was bi-convex (bulging outwards on both sides), and the lens of the far end (the objective lens) was plano-convex (flat on one side and bulging outwards on the other side). This advanced microscope had a 3 to 9 times power of magnification. Zacharias Janssen's father Hans may have helped him build the microscope.

DA VINCI, LEONARDO Leonardo da Vinci (1452-1519) was an Italian inventor, artist, architect, and scientist. Da Vinci had an interest in engineering and made detailed sketches of the airplane, the helicopter (and other flying machines), the parachute, the submarine, the armored car, the ballista (a giant crossbow), rapid-fire guns, the centrifugal pump (designed to drain wet areas, like marshes), ball bearings, the worm gear (a set of gears in which many teeth make contact at once, reducing the strain on the teeth, allowing more pressure to be put on the mechanism), and many other incredible ideas that were centuries ahead of da Vinci's time.

GALILEI, GALILEO Galileo Galilei (1564-1642) was an Italian mathematician, astronomer, and physicist. Galileo found that the speed at which bodies fall does not depend on their weight. Galileo did extensive experimentation with pendulums, finding that they nearly return to the height at which they were released, that different pendulums have different periods (independent of bob weight and amplitude), and that the square of the period varies directly with the pendulum's length. Galileo was the first person to use a telescope to observe the skies (in 1609), after hearing about Hans Lippershey's newly-invented telescope. Galileo discovered the rings of Saturn (1610), was the first to see the four moons of Jupiter (1610), observed the phases of Venus, studied sunspots, and discovered many other important phenomena. In 1593 Galileo invented the thermometer. After publishing the many discoveries he made using his telescope, including the motion of the Earth around the Sun (the Copernican system), Galileo was accused of heresy by the Inquisition (in 1633).

GLOBE Martin Behaim (1459-1537) was a German mapmaker, navigator, and merchant who made the earliest globe, called the "Nürnberg Terrestrial Globe". It was made during the years 1490-1492; the painter Georg Glockendon helped in the project. Behaim had previously sailed to Portugal as a merchant (in 1480). He had advised King John II on matters concerning navigation. He accompanied the Portuguese explorer Diogo Cam (Cão) on a 1485-1486 voyage to the coast of West Africa; during this trip, the mouth of the Congo River was discovered. After returning to Nürnberg in 1490, Behaim began construction of his globe (which was very inaccurate as compared to other maps from that time, even in the areas in which Behaim had sailed). It was once thought that Behaim's maps might have influenced Columbus and Magellan; this is now discounted. Behaim may have also developed an astrolabe. Behaim's globe is now in the German National Museum in Nürnberg.

JANSSEN, ZACHARIAS Zacharias Janssen was a Dutch lens-maker who invented the first compound microscope in 1595 (a compound microscope is one which has more than one lens). His microscope consisted of two tudes that slid within one another, and had a lens at each end. The microscope was focused by sliding the tubes. The lens in the eyepiece was bi-convex (bulging outwards on both sides), and the lens of the far end (the objective lens) was plano-convex (flat on one side and bulging outwards on the other side). This advanced microscope had a 3 to 9 times power of magnification. Zacharias Janssen's father Hans may have helped him build the microscope.

MICROSCOPE The microscope may have been invented by eyeglass makers in Middelburg, The Netherlands, invented sometime between 1590 and 1610. Hans and his son Zacharias Janssen are mentioned in the letters of William Boreel ( the Dutch envoy to the Court of France) as having invented a 20X magnification microscope. Robert Hooke used an early microscope to observe slices of cork (bark from the oak tree) using a 30X power compound microscope. He published his observations in "Microgphia" in 1665. In 1673, Antony van Leeuwenhoek discovered bacteria, free-living and parasitic microscopic protists, sperm cells, blood cells, etc., using a 300X power single lens microscope.

PENCIL The "lead" pencil (which contains no lead) was invented in 1564 when a huge graphite (black carbon) mine was discovered in England. The pure graphite was sawn into sheets and then cut into square rods. The graphite rods were inserted into hand-carved wooden holders, forming pencils. They were called lead pencils by mistake - at the time, graphite was called black lead or "plumbago," from the Greek word for lead (it looked and acted like lead, and it was not known at the time that graphite consisted of carbon and not lead). In 1795, the Nicholas Jacques Conte (a French officer in Napoleon's army) patented the modern method of kiln-firing powdered graphite with clay to make pencils of any desired hardness.

Galileo Galilei THERMOMETER The Thermometer was invented by Galileo Galilei in 1593. His thermometer consisted of water in a glass bulb; the water moved up and down the bulb as the temperature changed.