Microscope and telescope

1590 Microscope and telescope

The book of science

Tom Sharp

Zacharias Janssen, Hans Lippershey, Jacob Metius, Cornelis Drebbel optics Microscope and telescope

Microscope and telescope

Zacharias Janssen, a street seller often in trouble and a counterfeiter of coins, or his father, or his son, or his neighbor Hans Lippershey, a spectacle maker, or Lippershey’s assistant— one of these people— invented the microscope, or, on similar principles, the telescope, or both. Other Dutch spectacle makers in Middelburg and Alkmaar including Jacob Metius and Cornelis Drebbel made similar claims.

Optical refracting

The simple single-lens optical refracting microscope uses a convex lens. The compound optical refracting microscope uses two convex lenses. A magnifying glass is simple single-lens optical refracting microscope. The first optical refracting telescopes had a convex objective lens and a concave eyepiece lens. Kepler’s improved telescope had two plano-convex lenses.

Telescoping history

The Dutch telescopes magnified distant objects three times. Galileo Galileli’s improved telescope, in 1609, magnified eight times. In 1610, Galileo observed the moons of Jupiter with one of his telescopes that magnified thirty times which he called a perspicillum or his occhiale or “eyepiece” and which in 1611 Giovanni Demisiani called a telescope. In 1609, Galileo made a compound microscope that he called an occhiolino, his “little eye,” which in 1625 Giovanni Faber called a microscope. Isaac Newton in 1668 built the first reflecting telescope using a curved mirror instead of lenses. Christiaan Huygens in 1733 made an achromatically corrected microscope.


An eyeball bends light to a little retina. The lens in the ball angles the light. A line of refractions in the eye a series of refinements in the mind make a small scope seem large.

Galileo adjusted lenses for his scopes using trial and error, as the early Dutch makers might have done. Johannes Kepler and Christiaan Huygens, however, were mathematicians, and they established a theoretical understanding of how lenses worked, which resulted in improvements in magnification and clarity.

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