P.D. Martin lived in Simon's Town from 1860 or earlier. In 1868 he was appointed consular agent for the United States at Simon's Town, and the next year in addition vice consul for the North German Confederation. In July 1872 he published a paper titled "Stone implements and shell caves" in the Cape Monthly Magazine (Series 2, Vol, 5 (No. 25), pp. 53-55). In this paper he described five bored stones, found at various places along the coast, and mentioned that, according to older people, these were used by "the natives" to add weight to digging sticks. He also described stones with worn surfaces, grooves or hollows, usually found at shell mounds, and speculated on their possible uses. Finally, he noted that coastal shell mounds are undoubtedly kitchen middens and that they occur in places where there was a dense clump of melkbos (shrubby or bushy plants of the genus Euphorbia or the family Asclepiadaceae), which would have provided shelter. In a comment on the article (pp. 55-57) J.H. Bowker* provided additional information on these topics. In his paper Martin refers to a query he published in the Cape Monthly Magazine in July 1858, relating to the way of life of early coast dwellers. His interest in the prehistory of the Cape was therefore of long standing.
At the time when his paper was published Martin had just presented the South African Museum with archaeological material collected from kitchen middens along the coast of the Cape Peninsula. The material comprised a "very perfect" human skull, specimens of pottery, a few half-worn rubbing stones, spear points and arrow-heads.
He may have been the author of an article published under the name "Martin" in the South African Commercial Advertiser in March 1845, entitled "Cape of Good Hope geology, mineralogy and soil". The author briefly described the geological strata in the neighbourhood of Cape Town and in the Transkei, as well as some mineral deposits, mineral springs, salt pans, and the soils of the colony.
Martin was a member of the South African Philosophical Society in 1879, but not for long. He died before or in 1885, for in that year his wife donated his "native artifacts" to the South African Museum.