William Dawes was born in Portsmouth in 1762. The exact date is not known but there is evidence that he was baptised on 17th March 1762. He was the eldest son of Benjamin Dawes who was the Clerk of Works in the Ordnance Office in Portsmouth. Nothing is known of his early life; history recording that he was gazetted second lieutenant in the marines on 2 September 1779 and in September 1781 was wounded aboard HMS Resolution in the action against the French off Chesapeake Bay.
On 13th May, 1787, Dawes sailed from England on board HMS Sirius under Captain Arthur Phillip in what was later to be called Australia's "First Fleet", the mission being to set up a penal colony in Australia. Dawes had previously been known to be a competent astronomer, a fact siezed upon by the Astronomer Royal, Rev. Dr Nevil Maskelyne and the Board of Longitude who supplied instruments and books for an observatory which they hoped would be built in New South Wales.
The Sirius arrived in Australia in January 1788. Shortly afterwards Dawes began to build an observatory on what is now Dawes Point whilst maintaining his responsibilities as an engineer and surveyor. He took part in several expeditions in which his training and skill in computing distances and in map making were invaluable. From April 1788 he was able to spend more time on the construction of the observatory which by all accounts was a sturdy octagonal structure made of wood with a canvas roof alongside which was a second building in which Dawes lived.
Dawes was keen to devote much of his time taking the astronomical observations requested by the Board of Longitude and the search for a comet, but his services as surveyor were in continuous demand and work proceeded rather slowly. In October 1788 he applied for and was granted a further three years service in the colony during which he continued taking observations in tandem with his surveying duties. Records show that he completed most of the tasks requested by the Board in the ensuing years and by 1791 Dawes was thinking in terms of settling in the colony on a permanent basis. This, however, was not to be. He fell out badly with the Governor, Captain Phillip, who refused to sanction a renewal of Dawes' residence, and so in December 1791 he left Australia with the Marines, having largely demolished the observatory and taking all the instruments with him.
Soon after returning to England in 1792 Dawes was promoted to 1st Lieutenant and in July was sent to Sierra Leone as councillor to the governor, whom he succeeded in December. This lasted until 1794 when once more he returned to England and married Judith Rutter on 29 May 1794 in Portsea. The following year he went again to Sierra Leone where he stayed a further year. On 19th March 1799 a son, William Rutter Dawes was born to William and Judith. In the same year he was mathematics master at Christ's Hospital and was thus available in June 1799 to give evidence before a committee of the House of Lords considering a bill to limit the slave trade.
A third term in Sierra Leone followed the death of his wife Judith in 1800 which lasted until 1803. The ensuing years saw Dawes adopt an advisory role in various capacities, travelling extensively, especially to the Caribbean and Africa. He was married for a second time to Grace Gilbert on 25 May 1811 in London. In 1813 he offered to act as a Church Missionary Society agent and went to Antigua where he remained until his death in 1836, aged 74.
A scientific paper on the gravitational meaasurements made by William Dawes can be found at:-
An assessment of William Dawes work in understanding the Aboriginal language of Sydney can be found at:-