Walnut and brass scale model (1:50 approx) of the 'Great Paris Telescope' exhibited at the 1900 Paris Exposition, a stationary 1.25 metre refracting telescope (57 metres long) with a 2 metre mirror siderostat.

This is a model of the Great Paris Telescope.

The original was the largest refracting telescope ever built. It used a glass lens 1.25 metres in diameter in a fixed tube 57 metres long. Light was directed into the telescope by a two metre glass mirror on a massive 15 tonne mounting. Built for 1.5 million francs by a private consortium, this extraordinary instrument was constructed by Paul Gautier and then displayed in the Palais de L'Optique adjacent to the Paris Exposition of 1900. Everyday until midnight the public could queue for views through the great telescope after which it was used by the astronomer, M. Antoniadi. Despite its popularity, admission fees to the exhibition only recouped half the costs incurred. Later, hopes of selling the instrument to the French government failed and barely a year after completion it was scrapped, with only the optics being saved.

In 1993, a chance request to the Science Museum from a dealer to identify a mystery object led to the discovery of this model, the only known 1:40 scale representation of the ill-fated Great Paris Telescope. Made of walnut and brass it differs somewhat from the finished telescope and is thought to be a demonstration piece constructed for the syndicate who built the actual telescope. The utilitarian finish suggests it was probably made by a pattern maker rather than a professional model maker as it is too crude to be effective for publicity purposes.