A catalogue of instruments, prints, and books offered for sale by Benjamin Martin in 1762 included the following, under the category of Instruments invented or improved, by B. Martin:
"A compleat Apparatus of Optical Instruments in Brass, consisting of a new universal compound Microscope, a Solar Microscope of the latest Improvements; with a Megalascope, and Stand for [James] Wilson's Microscope. The Whole is furnished with every thing necessary for the nicest Observations with the Microscope."
The 'megalascope'
Though both unsigned, these two compendia (Images 1 & 2) were almost certainly sold by Martin, and they contain all of the apparatus listed. The "universal compound Microscope", "Solar Microscope", and "Wilson's Microscope" were all standard designs of the mid-18th century, but the "Megalascope" was Martin's own invention. Martin himself described the instrument, in a pamphlet of 1738:
"By a MEGALASCOPE is understood an Instrument which gives a magnified View of all the larger Sort of small Objects, and is sometimes called a Fossil-Microscope, Cloth Microscope, &c ... the Objects are so much magnified, and their Parts so separate and distinct, that we scarcely know them in this new Point of View, or can reconcile them to the Ideas they impress on the Mind by the natural Appearance."
Martin here suggests that customers should purchase and use the megalascope because it showed objects to be completely different from their appearance to the naked eye. He was using the unfamiliar nature of the microscopical world as a selling-point. In this context the microscope can be seen as a curiosity, able to engage and fascinate an audience, by showing familar objects in a new way.
