Riding the wave

Equatorial Theodolite

An interesting aspect of the English makers of scientific instruments was the appearance, midst of the eighteenth century, of large factories, that built instruments used in all fields of scientific research. At that time thus disappears the figure of the artisan, replaced by industry managers and skilled workers, and appear the figures of the technologist and of the scientist.

Jesse Ramsden (Salterhebble 1735 - Brighton 1800), British physicist and leading british craftsman of the XVIII century, was active in many different fields: manufacturer of precision devices, he created a wire micrometer used to measure the arcs of the sextant and of the geodesic circles. He created dividing tools and precision scales , perfected optical instruments and theodolites, and built a triboelectrostatic machine. He became famous mainly since 1770, when he began to make astronomical instruments.

Equatorial Theodolite

The Hydrographic Institute of the Navy owns a portable Equatorial Theodolite made by Ramsden after 1780, by modifying a model described by Van Short in 1749. It's a tool for astronomical observations, with equatorial and altazimuth mount, that allows measurements of right ascension and declination of stars.
By Paola Presciuttini
it