In the 17th century Robert Hooke produced a revolutionary bestseller, helped rebuild London after the Great Fire, and was a renowned experimenter, inventor, musician and artist. Hooke contributed to astronomy, geology, structural engineering and chemistry. He was 'England's Leonardo'.

Robert Hooke - England's Leonardo

He also created one of the world's first compound microscope. He looked at dead bark/cork - the empty spaces looked like "empty rooms" & were named "cells".

PS: AVH later also created a microscope but saw living microorganisms.

Yes, you're right, Sadhana, Hooke was the first to use the term "cells" microscopically. Although he was looking at cork, which wasn't alive, the term was transferred later to living things.

But Hooke didn't invent the microsope. Zacharias and Hans Jansen, Dutch spectacle makers, produced the first known primitive compound microscope in 1595. However many decades later Hooke used his own improved microscope for the first serious scientific study. Micrographia was published in 1665 – 2015 is the 350th anniversary of its publication.

Anton van Leeuwenhoek was inspired to improve the lenses he made for his microscopes, and to use them for the study of living things. Although he'd been sending letters about his research to the Royal Society for some time, even the society balked when he described seeing teensy living things - microorganisms, we call them today. It took a while to confirm their existence.

The Monument to the Great Fire of London still stands and the nearby Underground station is named Monument for it. Christopher Wren tends to get the credit, but it was a collaboration with Robert Hooke. In fact, there is evidence that suggests that Hooke was mainly responsible.

Interestingly, Hooke hoped to use the monument for scientific purposes as well. It could double as a zenith telescope. There's a small room at the base for a laboratory and a trapdoor at the top of the column. But it turned out to be unsuitable for this because of the column's movement in the wind. But the steps are all precisely six inches high, so it was possible to use the monument for gravity experiments and to measure the effect of height on atmospheric pressure. But that didn't last long, because the vibration from passing traffic – even in those days – made it impossible.

This year is the 350th anniversary of the publication of Hooke's Micrographia. There are exhibitions here and there in Britain comemmorating this astounding book that introduced people to the invisible world of the very small.

The Royal Society in London, of course, has an exhibition to celebrate this event, but there are also exhibitions at the National Library of Wales in Aberystwyth and the Victoria Gallery and Museum in Liverpool. There have been - or will be - among others, events at Freshwater (where Hooke was born), Christ Church College Oxford (where Hooke studied), and Exeter (by the Royal Society of Biology).