Hellins, John (d. 1827), mathematician and astronomer, was born in or near North Tawton, Devon, into a poor family. His father worked as a labourer at Ashreigney, near Chulmleigh. Hellins was bound as a parish apprentice to a cooper at Chulmleigh and worked at that trade until he was about twenty, during which time he taught himself elementary mathematics. He then became master of a small school at Bishop's Tawton, and made the acquaintance of the astronomer Malachy Hitchins, vicar of St Hilary and Gwinear, Cornwall, through whose influence he was appointed an assistant in the Royal Observatory at Greenwich under Nevil Maskelyne. While so employed he studied Latin and Greek and qualified for holy orders. He was curate of Constantine in Cornwall (177983) and afterwards of Greens Norton, near Towcester, and in 1790 was presented to the vicarage of Potterspury in Northamptonshire. On 10 November 1794 he married Anne, née Brock of North Tawton, with whom he had one son. Admitted as a ten-year man at Trinity College, Cambridge, in July 1789, he finally graduated BD in 1800. In 1817, with financial help from the fourth duke of Grafton, he opened a school in Potterspury, which prospered under its first headmaster, Thomas Hall.
Hellins published nine papers in the Philosophical Transactions of the Royal Society between 1780 and 1811. He was elected FRS in 1796 and two years later won the society's Copley medal for his improved solution of a problem in physical astronomy, by which swiftly converging series are obtained which are useful in computing the perturbations of the motions of the Earth, Mars, and Venus by their mutual attractions. Comparing a paper by Hellins from the Philosophical Transactions (On the rectification of the hyperbola) with one on the same subject by Robert Woodhouse, the Gentleman's Magazine contrasted the obscurity of the latter to the plain and perspicuous style of Hellins's work.
In 1787 Hellins edited a new edition of Daniel Fenning's Young Algebraist's Companion and the following year published his own Mathematical Essays on Several Subjects: Containing New Improvements and Discoveries. In 1791 he wrote two of the tracts in Francis Maseres' Scriptores logarithmici; between 1795 and 1814 he contributed a series of mathematical reviews for the British Critic; and in 1801 he superintended the publication of an English translation of Maria Agnesi's Instituzioni analitiche ad uso della gioventù italiana (1748). In 1806, when the then minister of war was projecting his new military system, Hellins furnished all the calculations and tables on which it was based.
Hellins died on 5 April 1827 at Potterspury and was buried there four days later. Paying tribute, Davies Gilbert, then president of the Royal Society, described him as one of those extraordinary men who, deprived of early advantages, have elevated themselves, by the force of genius and of industry, to a level above most persons blessed with regular education (Nichols, 7.66970) His wife survived him. In 1990 the village school at Potterspury was renamed the John Hellins Primary School.
R. E. Anderson, rev. Adrian Rice
Nichols, Illustrations, 6.4043 · Nichols, Illustrations, 7.66970 · R. Polwhele, The history of Cornwall, 7 vols. (18038); repr. with additions (1816), vol. 5, p. 107 · Boase & Courtney, Bibl. Corn., 1.227 · Venn, Alum. Cant. · GM, 1st ser., 85/1 (1815), 1822