Student "Iron" Microscope Powell & Lealand (c.1846)
Hugh Powell (1799–1883) began making microscope components under his own name. In 1841, together with Andrew Ross and James Smith, he founded the Royal Microscopical Society (RMS) out of the Microscopical Society of London, founded in 1839, and they became leaders in the development of microscopes. He joined forces with his brother-in-law Peter Lealand and they made some legendary microscopes, very heavy, of great quality and, over time, considered to be the best of the Victorian era. They were made in small quantities and for 60 years hardly changed. This first model is known as the No. 3, since they later designed an improved one (the No. 2).In 1869 they presented an even larger model known as the No. 1. The No. 4 was a smaller, foldable and portable model. They also made a model for students known as “Iron” because of its functional base. It had small variations but was characterized by its simplicity and by having a focusing system integrated inside the tube. His company manufactured only 600 copies in its entire history and never employed more than 5 workers, so many of the copies were customized on demand and took more than 1 year to be delivered. They were not numbered and only indicated the year of construction. They also specialized in the design and construction of high-quality lenses.
This is an example based on the Lister frame, made by Powell & Lealand and retailed by Carpenter. It is known as the "Student" or "Iron" as the stem and frame are made of black iron. Although most of these examples only have coarse focusing, this one also has fine focusing. The focusing screw activates a pinion which acts on a rack which is built inside the body tube itself. Ross and, especially, Dancer, used the same focusing system in their early models, switching to the rack and pinion system later. It is uncertain when Hugh Powell made his first example, but it is considered that this could have been around 1838-40 and his last example dates from 1911. The lens has a pre-RMS thread so must be before 1848.
References: "Billings Microscope Collection" pag 44, fig. 83
H. Moe, "The Story of the Microscope", pag 171
G. Turner, "Great Age of the Microscope", pag 147
G. Turner, Collecting Microscopes, pag 75
Links: https://www.microscope-antiques.com/pliron.html
http://www.antique-microscopes.com/photos/PL_student.htm
https://golubcollection.berkeley.edu/19th/279.html
https://www.perea-borobio.com/45b-microscopio-para-estudiantes-lealand-powell-1841-londres/
https://micro.magnet.fsu.edu/primer/museum/powelllealandironstand1911.html