Jesse Ramsden was a famous scientific instrument maker and inventor, and maker of the first effective screw-cutting lathes.
He was born at the Elephant & Castle, Salterhebble, on 6th October 1735. His father was an inn-keeper.
He attended Heath Grammar School for 3 years, leaving when he was 12 years of age.
Originally working in the textile trade being apprenticed to a cloth-maker, he moved to London in 1755 and was apprenticed to a maker of scientific and mathematical instruments. By 1762, he had his own business in London, and was recognised as the most skilful designer of mathematical, astronomical, surveying and navigational instruments of his time.
In 1765, he married Sarah, daughter of John Dollond.
He designed and produced a wide range of barometers, manometers, microscopes, astronomical, and surveying instruments – including the equipment used by Captain Cook to observe the transit of Venus in 1759. He improved the Hadley quadrant. Although the French scientist, Cassegrain, had proposed a design for a reflecting telescope in 1672, it was Ramsden, who, in the 1770s, found that this design reduces blurring of the image caused by the sphericity of the lenses or mirrors.
His instruments were used by Lord Nelson, and the Duke of Wellington, and at the Piazzi Observatory in Palermo, the Dublin Observatory. In 1793, he produced the largest telescope then in existence.
His theodolite was used to produce the first Ordnance Survey of Britain.
In 1773, he devised his circular dividing engine for graduating and marking the scales of scientific instruments accurate to 0·00001 inches, winning prizes – including an award of £615 – from the Commissioners of the Board of Longitude. He was elected Fellow of the Royal Society in 1786. He received the Copley Medal in 1795.
His work led to the large screw-cutting lathe designed by Henry Maudslay in 1797.
There are over 50 of his inventions in the Science Museum in London.
He died in Brighton on 5th November 1800.
There is a lunar crater – Ramsden – named in his honour
Page Ref: QQ_188
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