L. Powell travelled to various parts of the world and made a living demonstrating a so-called oxyhydrogen microscope - a projection microscope using as a light source a small piece of limestone heated to a very high temperature by means of an oxyhydrogen flame. [Oxyhydrogen is a mixture of two volumes hydrogen and one volume oxygen, which burns to form water without any gas left over]. The light source was the brightest that could be produced at the time and thus allowed the use of high magnification. Powell may have been related to the prominent British microscope manufacturer Hugh Powell, who made a name for himself in the eighteen-thirties and -forties. As part of his travels he visited the Cape Colony from June to September 1837. On 7 June that year he advertised in the South African Commercial Advertiser that he would present three lectures on the microscopic anatomy of plants, insects, etc., illustrated by the oxy-hydrogen microscope. His first lecture dealt with the instrument itself, the second with the microscopy of plants, and the third with the microscopy of tiny animals. The price of attendance for the three lectures was four shillings and sixpence, a substantial sum at the time.
C. Piazzi Smyth*, assistant at the Royal Observatory, Cape of Good Hope, appears to have attended the lectures, but was not impressed. In a letter to his father dated 8 August that year he described Powell as "a lubberly looking fellow [who] has a very bad delivery" (Warner, 1983, p. 83). However, the microscope was still of sufficient interest nine years later, when a lecture on it was presented in Cape Town by R. Stapleton*.
On 9 September 1837 Powell advertised a course of lectures on chemistry in the same newspaper. There were to be between 12 and 18 lectures on all aspects of the subject, illustrated by frequent experiments. The price for the course, one pound ten shillings, would have been affordable by well-off members of the community only and it is not clear whether there was sufficient interest for the course to be delivered.