Henry Maudslay

Measurement turns reality into numbers, and numbers into reality.

Henry Maudslay invented the high-precision screw lathe, and used it to produce his "Lord Chancellor" screw micrometer, the mother of all measurement instruments. This device was used to make other devices that Whitworth used to define the British standard screw thread, the mother of interchangeable parts; a #6 screw from anywhere would fit a #6 threaded hole, anywhere. It was used to make the ruling engine that produced the Paris meter standard. Essentially every modern measured object descends from the Lord Chancellor.

Maudslay also built the first semi-automated mechanical factory with Marc Isambard Brunel, producing 130,000 ship pulley blocks per year for the British Admiralty, ten times faster than prior factories. The Admiralty reneged on the contract, paying a fraction of the promised rate.

John Cantrell & Gillian Cookson (eds), Henry Maudslay & The Pioneers of the Machine Age (Stroud: Tempus, 2003).
- out of print, The History Press
- John Cantrell, Manchester Grammar School, retired
- Gillian Cookson
- Maudslay society, jay cee h dee 1 AT cam dot ac dot uk

Stars of Invention

Henry Maudslay is not well known, even amongst mechanical engineers, while more recent engineers (like Nikola Tesla) have many fans. I'd compare Tesla to Sirius, and Maudslay to Deneb:

			magnitude		distance
Inventor	Invention	star	visual	absolute	parsec	lightyear
Nikola Tesla	AC Induction Motors and Generators	Sirius A	−1.47	1.42	2.64	8.60
Henry Maudslay	Mechanical Precision, automated manufacturing	Deneb	1.25	-8.38	800	2600

So Tesla appears brighter in the sky, and "meteors" like Elon Musk or Thomas Edison briefly seem brighter than both, but Maudslay's contribution is (like Deneb) 8000 times brighter, though obscured by distance from modern awareness.