A chemist cannot pick up an atom. What a chemist can do is weigh things and measure volumes, and the whole of quantitative chemistry rests on a bridge between those two operations and the invisible particles underneath them. The bridge was proposed in 1811 by a Piedmontese lawyer turned physics…

On 19 September 1783 a large linen and paper balloon, painted blue and decorated with gold fleurs de lis, was inflated in the forecourt of the palace of Versailles over a fire of straw and wool. Louis XVI and Marie Antoinette were watching, along with a crowd estimated at over…

In 1801 a building in Munich collapsed on top of a fourteen year old apprentice mirror maker. He was dug out of the rubble alive, and the rescue was watched by the Prince Elector of Bavaria, who gave the boy money on the spot. Joseph Fraunhofer used it to buy…

In the spring of 1788 three men hired a boat at Dunglass on the Berwickshire coast and rowed east along the cliffs. One of them was a farmer and physician named James Hutton, who was looking for a particular arrangement of rock and had already found versions of it inland.…

The instrument stood in the Han capital of Luoyang and was about two metres across: a domed bronze vessel, sometimes described as resembling a wine jar, with eight dragon heads spaced around it. Each dragon held a bronze ball in its jaws. Below each dragon sat a bronze toad with…

Shen Kuo was a Song dynasty official who had been a finance minister, a hydraulic engineer, a diplomat sent to negotiate a border with the Liao, and a military commander. In 1082 an army under his overall command was defeated at Yongle by the Western Xia, tens of thousands of…

In 1088 a Chinese civil servant finished building a tower about ten metres high in the imperial capital of Kaifeng. Inside it, a water wheel turned one step at a time, released by a mechanism that let through exactly enough water to fill a bucket and no more. The wheel…

In 1890 the German Chemical Society held a celebration in Berlin to mark twenty five years since August Kekule had proposed the structure of benzene. In his speech he told the audience how the idea had arrived. He had been dozing by the fire in Ghent, watching atoms dance in…

On 1 August 1774, in a laboratory in Wiltshire, an English clergyman focused sunlight through a large lens onto a sample of red mercury calx sealed in a glass vessel. A gas came off. He collected it, and found that a candle burned in it with a fierce brightness and…

In the winter of 1763 the University of Glasgow sent a broken model to its instrument maker for repair. It was a small working Newcomen engine used for teaching, and it would not run properly: a few strokes and it ran out of steam, every time. James Watt was 27…