Observatory House was an observatory in Slough

Slough

Slough is a borough and unitary authority within the ceremonial county of Royal Berkshire, England. The town straddles the A4 Bath Road and the Great Western Main Line, west of central London...

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

. It was built, run and used by the astronomer William Herschel

William Herschel

Sir Frederick William Herschel, KH, FRS, German: Friedrich Wilhelm Herschel was a German-born British astronomer, technical expert, and composer. Born in Hanover, Wilhelm first followed his father into the Military Band of Hanover, but emigrated to Britain at age 19...

, and his sister Caroline

Caroline Herschel

Caroline Lucretia Herschel was a German-British astronomer, the sister of astronomer Sir Friedrich Wilhelm Herschel with whom she worked throughout both of their careers. Her most significant contribution to astronomy was the discovery of several comets and in particular the periodic comet...

. The famous '40-foot telescope

40-foot telescope

William Herschel's 40-foot telescope, also known as the Great Forty-Foot telescope, was a reflecting telescope constructed between 1785 and 1789 at Observatory House in Slough, England. It used a 120 cm diameter primary mirror with a 12 m long focal length . It was the largest telescope in...

' - at that time the largest in the world - was housed there in the late 18th century and early 19th century.

The main house was on Windsor Road. There was also a small cottage on the land. Herschel moved there on 3 April 1786. John Herschel

John Herschel

Sir John Frederick William Herschel, 1st Baronet KH, FRS ,was an English mathematician, astronomer, chemist, and experimental photographer/inventor, who in some years also did valuable botanical work...

 was born in the house, and William died there on 25 August 1822. John Herschel and his family moved out of the house to Hawkhurst

Hawkhurst

Hawkhurst is a village and civil parish in the borough of Tunbridge Wells, Kent, England. The parish lies to the south-east of Tunbridge Wells. Hawkhurst itself is virtually two villages...

in 1840. Observatory House was later demolished. A monument remains on Herschel Street, close to where the 40-foot telescope was located.