The microscope as we know it has its origins from magnifying glasses used in the first century AD mainly to look at smaller things or to start fires by focusing the rays of the sun through the lenses. The word lens itself comes from the Latin ‘lentil’ and the Romans called lenses such because the clear glasses resembled lentil seeds in being thicker in the middle and tapering down the edges. These magnifying lenses were used later on in the thirteenth century in frames to be worn as glasses.

It is only in the late 1500s, when the father and son team of spectacle makers Hans and Zaccharias Janssen began experimenting with the lenses, that compound microscopes— that is, microscopes with two or more lenses— were invented. They started by placing several lenses inside a tube and noticed that the objects near the end of the tube looked larger than they are as seen through a normal magnifying glass. Upon hearing about the Janssens’ discoveries, Galileo began experimenting on magnifying glasses on his own, improving on both the microscope and telescope. By adding a focusing device on his microscope, he began studying the heavens with his telescope that was made from these lenses. Read the rest of this entry »