See also

Family of Samuel DUNN and Elizabeth HARRISON

Husband: Samuel DUNN (c. 1723-1794)
Wife: Elizabeth HARRISON ( - )
Marriage 2 Jun 1763 St Margaret, Westminster, London, England
Samuel, bachelor of St Luke's Chelsea, and Elizabeth spinster of St Margarets Westminster. married by Licence.

Husband: Samuel DUNN

Name: Samuel DUNN1
Sex: Male
Father: John DUNN (c. 1688-c. 1744)
Mother: Alice HARRIS? ( - )
Birth c. 1723 Crediton , Devon, England
Baptism 7 Feb 1723 (age 0) Crediton , Devon, England
Occupation Mathematician, Cartographer
Death Jan 1794 (age 70-71) St Dunstan in the West, London, England
Burial 23 Jan 1794

Wife: Elizabeth HARRISON

Name: Elizabeth HARRISON1
Sex: Female
Father: -
Mother: -

Note on Husband: Samuel DUNN

Teacher in Crediton, then London - see National Dictionary of Biography below

Dunn, Samuel (bap. 1723. d. 1794), teacher of mathematics and navigation, was born in Crediton, Devon, and baptized there on 7 February 1723. the son of John (d. 1744) and Alice Dunn. Nothing is known of his own education, which gave him a competence in mathematics, but by the age of nineteen he was keeping his own school and teaching writing, accounts, navigation, and other mathematical sciences. This building was destroyed in the fire which swept through Crediton in August 1743 and Dunn then taught in a school installed in the Old Church House until December 1751, when he went to London.

There Dunn taught in different schools and gave private lessons. He first caught public attention as the inventor of the 'universal planispheres, or terrestrial and celestial globes in plano, an economical method of teaching spherical geo'metry without the expense of purchasing actual globes'. His book The Description and Use of the Universal Planispheres (1759) was the first of a stream of textbooks which provided his students with all aspects of mathematics and navigation, both theoretical and practical. In 1758 Dunn became master of an academy at Ormond House. Paradise Row, Chelsea, where there was a good observatory from which he observed a comet in January 1760 and the transit of Venus in 1761. This and other astronomical news was

communicated in his nine letters to the Royal Society, where he was a frequent visitor, though never elected a fellow. He married in 1763 a Mrs Harrison, keeper of a girls' school at Brompton Park, Kensington, but discovered only after the marriage that she was heavily in debt, which then devolved on him. He considered declaring himself bankrupt, but before the matter was resolved she left him.

Dunn continued to live at Brompton Park, reverting to private teaching. In July 1764 he was in Paris, though the length and purpose of his visit is not known. When the Nautical Almanac was introduced (for the year 1767) the board of longitude ruled that all ships' masters appointed henceforth had to have a certificate of competence, and until 1771 Dunn was among the teachers authorized to sign these certificates. Dunn was similarly involved with the East India Company as a recognized teacher, and from the 1770s he prepared charts for far eastern waters. In A New Variation Atlas (1776). and A New Epitome of Practical Navigation, or, Guide to the Indian Seas (1777), dedicated to the company, Dunn introduced an original solution to the

double-altitude problem. Where the approximate latitude was known two observations were to be taken of the sun's altitude, and the time elapsed between observations noted; calculations following Dunn's formula then yielded the true latitude. This solution was a remarkable discovery and later formed the basis of the 'trial and error' method for finding longitude. It also led towards position-line navigation. In 1780 he succeeded William Herbert as editor of the New Directory for the East Indies and in 1787 the East India Company's hydrographer, Alexander Dalrymple, made plates of his charts available so that Dunn could group and print them for the sixth edition of the Directory.

Dunn also sought to improve instruments for navigation and cartography. An angular micrometer which he

demonstrated to the Royal Society in May 1761 was made for him by the firm of Heath and Wing in the Strand, and his pantograph, described in The Theory and Use of the Pantographer (1774), was made by their successor, Thomas Newman. In 1768 he showed to the board of longitude models of a sextant for taking large angles, for which he was awarded £20. The instrument maker Jesse Ramsden was asked to construct them, with a recommendation that the instrument should be tested by an expedition going to the Arctic regions to observe the 1679 transit of Venus. Dunn himself was invited by the astronomer royal to observe the transit from the Royal Observatory, Greenwich, in the evening of 3 June.

Not all Dunn's proposals to the board of longitude met with approval. His method of finding the longitude of

ports and another for drawing magnetic isolines at sea were rejected, for example. His Theory and Practice of Longitude at Sea (1786), dedicated to the Company of Merchants, was however ahead of its time. Watches were still rare in his day and the method matured only after his death. From 1774 Dunn was residing at 6 Clement's Inn, Westminster, and in July 1777 he was at 8 Maiden Lane, Covent Garden, but by September 1780 he was at 1 Boar's Head Court, Fleet Street, where he died in January 1794. He was buried at St Dunstan-in-the-West on 23 January. His bequests, mainly to family members, included a sum to endow a master to teach all aspects of mathematics and navigation to six boys at Bowden Hill School, which was later known as 'Dunn's school'. On 10-14 April 1794 Sothebys sold his books and maps in 1000 lots, many of which were bought by Dalrymple, followed by eighty lots of his instruments, and several hundred of his own books in sheets. GORDON GOODWIN. rev. ANITA MCCONNELL


Sources C. Cotter, A history of nautical astronomy (1968) o D. Howse, Nevfl Moskelyne: the seaman's astronomer (1989) o A catalogue of the valuable library and mathematical instruments, &c., of Mr Samuel Dunn (1794) [sale catalogue, Leigh and Sotheby, London, 10-14 April 1794] o minutes of the Board of Longitude, CUL, RG014/2,5 o Nichols, Illustrations, 4.545 o BL, Add. MS 4305, fols. 88-9: Add. MS 28536, foL 241 o T. W. Venn, 'Crediton als Critton als Kirton and herabouts', 2 vols., 1957, Society of Genealogists, 2.203-4 o will, PRO, PROB 11/1240, sig. 16 o parish register, Devon RO [baptism)





Founded with a legacy from Samuel Dunn, a native of Crediton, whose father seems to be that John Dunn who signed the Association Rolls of 1689 and who died in 1744. His grave, as plotted by his son, habituated to measure the stars, was 20 yards from the north-west corner of the church. From the age of 19 Samuel Dunn had kept his own private school at Crediton, but when it was destroyed by fire in 1743 he took a post in the English School, of which he was promised the headmastership when it should fall vacant. Not waiting for this, about 1751, he opened again for himself at Ormonde House, Chelsea.


"S. Dunn - Teacher of the Mathematics, boards young gentlemen. Teacheth Penmanship, Mercantile Accounts, Navigation. Fortification, Astronomy etc"


In 1765 he married a Mrs. Harrison who kept a girls school at Brompton Park, near Kensington - to all outward appearances a flourishing establishment. In truth however the lady was heavily in debt, a fact concealed until after the marriage, by which her liabilities in law automatically devolved upon her husband. Because of his love for her Dunn accepted the situation, hopeful that after his assets were disposed of in bankruptcy, they could start afresh. But at this juncture his wife decamped, never to return. Dunn was plucked - "I can", he said, "seek no business without the hazard of being arrested, cannot appear in any decency for want of my apparel, and can do no teaching for want of my books." Friends, however, found him the means to continue his school, in which he acquired a growing reputation as a mathematician and writer on nautical astronomy . The Astronomy of the Fixed Stars, The Daily Table of Nautical Science, Discovery of the Law whereby Deviation of the Compasses is Caused, and many other works, but his chief claim to notice was his


Universal Planisphere, or the terrestrial and celestial globes in plano, by means of which problems of geography, astronomy and navigation could be worked out with the same certainty and ease as the globes themselves.


In 1788 a committee appointed by the Hon. East India Company to report on Dunn conceived so high an opinion of his abilities that he was engaged as examiner in mathematics to their cadets., at which time he lived at No 1 Boar's Head Court, Fleet Street. He also applied himself in picking out the safest and most direct routes to the East Indies and other parts of the world: and in 1792,when presenting the Hon company with one of his newest works, expressed the wish that it would be instrumental in preserving their valuable shipping.


Samuel Dunn, of whom Kirton should be proud, died in 1794, and by his will (proved by his kinsman William Dunn, excise man of London) left his wife £10 only - "She having withdrawn herself from me for 30 years". He being childless his estate went to his cousins at Crediton, William, Thomas and Mary Dunn [my g-g-g-g-grandmother. NH], subject to a bequest of £600 in Bank of England 5 per cents for the funding of a school (by the twelve Governors of the Church) in which writing, navigation, the lunar methods of taking longitude at sea, planning, drawing and surveying should be taught to six boys, preferably those named Dunn or Harris, otherwise to boys of the district belonging to the Established Church. The town was thus given an opportunity of becoming an incubator of seamen scientifically trained for their profession, but in that direction at least, the scheme seems to have failed.


The masters were to be of the Church of England, but not in holy orders, and the school was first opened in 1794 by Mr. Richard Gilbert. William Webber followed in 1814, and twenty years later Mr. Thomas Evans Jones was appointed, who was an ex-naval officer and during whose time it was known as the Nautical School. It was on Bowden Hill in 1843 when it was destroyed by fire, but was re-opened in the newly made Market Street, where it remained until Evans Jones handed over to a Mr. Martin at 9 Union road. The latter made a bad bargain in assigning "half dividends to his predecessor during his lifetime, for Thomas Evans Jones hung on to this easy money with such pertinacity that it was poor Martin who first took the long vacation. Between Mesdames Wellingtons' kindergarten and his entry to the Grammar School this writer [Venn] was for a year or two at Dunn's foundation, when it was behind No 35 High Street, and was run by a Mr. and Mrs. Simpson - The Long and The Short of it. For some reason the school moved back to the rebuilt house on the old site at Bowden Hill, [subsequently the offices of the Rural District Council] where it was when merged into the Grammar School, of which fact no mention is made in the [School's] Four Hundredth Anniversary Brochure printed in 1947.


from T. W. Venn, 'Crediton als Critton als Kirton and hereabouts', 2 vols., 1957, Society of Genealogists, 2.203-4


1"Nick Heard". This GEDCOM is predominantly the work of Nick Heard, but it incorporates the collaborated work of many other family historians. You are welcome to use the information herein but please acknowledge the source. Every effort has been made to ensure the data is accurate, but any use you make of it is entirely at your own risk. (c) Nick Heard 2009