Pierce Morton, of Kilnacrott, County Cavan, Ireland, was a Cambridge mathematician who qualified as Master of Arts (MA). He produced two publications early in his career. One was a paper, "On the focus of a conic section", in the Philosophical Transactions of the Royal Society (1830), the other a book, Geometry, plane, solid and spherical, in six books; to which is added, in an appendix, the theory of projection... (London, 1830, 272p).
On 1 November 1851 Morton was appointed to succeed G.R. Smalley* as third assistant at the Royal Observatory, Cape of Good Hope, under the direction of Thomas Maclear*. Assuming duty on 26 November, his work consisted of daily measurements of the parameters of the earth's magnetic field, namely magnetic declination, magnetic inclination, horizontal and vertical field strength, and total absolute field strength. A few months later, on 12 March 1852, the magnetic observatory burnt down and though a court of enquiry was set up, no definite cause of the fire was discovered. Though the building was a complete loss, the instruments were saved and Morton was able to continue the observations. However, Maclear began to employ him also in astronomical work. As a result magnetic intensity measurements were stopped in October 1857 and inclinations in March 1858, though declinations continued to be recorded.
In the October 1857 issue of the Cape Monthly Magazine Morton published a short paper titled "Notes on the earthquake". He died in office in April 1859. The day after his death one Pierce Edward Morton - presumably his son - assumed duty at the Royal Observatory as fourth assistant, but resigned in July 1860 and went to America.