Hood, John (1720/21?–1783), land surveyor, was apparently born in Co. Donegal. There may have been two John Hoods, father and son, who were both surveyors; if so, it is impossible to disentangle their careers and dates of vital events. John Hood, surveyor, died in 1783, and there is evidence that another John Hood of Donegal died before 1806, but it is not known if this later individual worked as a surveyor. One John Hood is said to have been born in 1720 in Moyle, Co. Donegal; in 1776 one was a surveyor in Castle Cunningham, Co. Donegal. In 1772 Hood published at Dublin Tables of difference of latitude and departure for navigators, land surveyors . . . to enable his readers to follow his recommendation that the bearing of an object should be taken from its meridian, and also suggested that the surveyor's chain should be set at a length of one hundredth of an Irish mile. Hood's book described a surveying instrument, later known as ‘Hood's compass theodolite’, which, it has been said (DNB), was the forerunner of all theodolites used in Britain and America. It is possible that the instrument resembled a circumferentor more than the conventional theodolite, particularly since it is said to have included a compass. It is also claimed that Hood independently developed but did not patent a version of the quadrant before Hadley's 1730 invention became known in Ireland. Hood died 17 December 1783, aged 62.
His first wife was Martha King; they had at least two daughters. After Martha's death, Hood married his daughter's husband's sister, Jane McCay, and had at least four sons and two daughters. In 1798 Henry Hood, son of John Hood and also a surveyor in Co. Donegal, became insane after intense study and had to be confined. Another son was Matthew Hood, agent to the Abercorn estate 1796–1806; papers, showing how the estate was managed in his time, survive in the important Abercorn archive in PRONI. Matthew Hood was suspected of support for United Irish principles, and later emigrated to America, where his son Samuel (1800?–1875) published a legal treatise in 1847, and in 1844 an Account of the Society of the Friendly Sons of St Patrick (of Philadelphia).