The Draper Who Saw the Unseen

The Quality of the Thread

In the Dutch city of Delft, a place of luminous canals and meticulous painters, Antonie van Leeuwenhoek was a man of cloth. Born in 1632, his world was one of textures and threads, of selling linen, yarn, and ribbon from the shop he opened in 1654. He was a draper, a practical man in a prosperous city during the Dutch Golden Age. His concern was the quality of his goods. To inspect the weave, to count the threads per inch with an expert eye, drapers used magnifying glasses. It was this simple, commercial tool that first opened a door for him. He was not a scholar. He had no university education, knew no Latin or foreign languages, the lingua franca of European intellectuals. He was an apprentice in Amsterdam for six years, learning the cloth trade, before returning to his hometown to build a life. He married a draper’s daughter, Barbara de Mey, and secured a comfortable position as chamberlain for the Delft sheriffs, a respectable municipal job he would hold for nearly four decades. This provided security, an income that allowed a man to pursue a hobby. And Leeuwenhoek’s hobby became an obsession. The small lenses of the drapery trade were not enough. He wanted to see more, to see better. He began to grind his own. There, in his shop, surrounded by bolts of fabric, he taught himself the delicate art. He would take a small rod of soda-lime glass, heat its middle in a hot flame until it glowed, then pull it apart, creating two long, thin whiskers of glass. By reinserting the tip of a whisker into the flame, a tiny, perfect sphere of glass would form. This was his lens. He learned to grind and polish these minuscule beads with astonishing precision, creating lenses of a power and clarity no one had ever achieved. He mounted them between two small, flat plates of copper or silver, riveted together. A pin held the specimen on the other side, and a set of screws allowed him to adjust its position and focus. They were not like the compound microscopes being developed elsewhere, instruments with multiple lenses in a tube. Leeuwenhoek's devices were smaller, barely a couple of inches long, and required holding the lens almost directly against the eye. But they were powerful. While the finest compound microscopes of the day might magnify an object 50 times, Leeuwenhoek’s simple, single lens could magnify it by over 200, some perhaps even 500 times. He guarded his methods jealously, admitting there were aspects of their construction "which I only keep for myself."