This is an astronomical refractor telescope on an English equatorial mounting. The provenance of this telescope is doubtful as it was found at the Royal Observatory, but could have been used at the Observatory belonging to the Greenwich Hospital School.

The telescope is a double achromatic telescope with a focus of thirty inches and two setting circles. This telescope is on an equatorial mount, which refers to a type of frame that allows the telescope to move with the rotation of the Earth - one axis is pointed towards the celestial pole (roughly speaking towards the Pole star for the northern hemisphere), the other can then be turned so that the telescope is able to follow a star as the Earth moves. Equatorial mountings come in two main types, English and German. The English style mounting is the shape of a + sign; the German style mounting is more of a T shape.