The secretary of the Royal Society Robert Hooke was an exception among his learned colleagues in that he had to work for a living. He variously supplemented his income as professional surveyor and as maker of bespoke scientific instruments. He constructed a vacuum pump for the immeasurably rich Robert Boyle, perhaps the first high-technology scientific instrument in the modern sense of the word. High technologies develop by integrating autonomous skills into a new whole, while basic research stimulates this development through demanding measurements. In this case, the requirement was for a wide range of pressures without loss of precision, gas leaks, or deforming the pressure chamber. Hooke’s solution was for the sturdy chamber of the pump to be made by glassmakers, the smooth cylinder by gunsmiths, and the precise mechanism by watchmakers. Boyle was thus able to confirm convincingly previous authors’ reports that the product of pressure p and volume V  of a gas is constant, \(pV\sim \mathit {const}\) . Several years later, Mariotte showed that the volume increases linearly with the temperature, \(V/T\sim \mathit {const}\) . In 1811, Avogadro observed that volumes of gases that participate in chemical reactions appear in proportion to small natural numbers. His interpretation, that it was a consequence of atoms combining into molecules, became known as the molecular hypothesis.