III. HISTORY. 411 



183 Id. Object-Glass, Venetian, of 90 feet focal length. 



Royal Society. 



1831e. Original Reflecting Telescope, made by Sir Isaac 

 NewtOQ. Royal Society. 



1833. The Herschel 7-foot Telescope. The original in- 

 strument constructed by Sir W. Herschel. 



Royal Astronomical Society. 



The tube is 7 inches in diameter and 7 feet long. Both mirrors were 

 finished by Sir W. Herschel's own hands ; they are sound and whole, but are 

 much tarnished, and the large mirror was damaged in a fire some years since. 

 The framework of the stand is entire, but the moving screws, cords, &c. are 

 useless in their present condition. 



1734a. Newtonian Telescope, belonging to Sir W 

 Herschel, and used by him while living in Bath. He is said to 

 have discovered the planet Uranus by its means. Focus, 7 feet ; 

 diameter of speculum, 6^ inch. Edwin Smith. 



This telescope was purchased at Sir W. Watson's sale, Pulteney Street, 

 Bath, about 1860. It had apparently remained after Sir W. Watson's death 

 for some time in a lumber room of the house, and when purchased by Mr. E. 

 Smith a paper of directions for the use of the different eyepieces was dis- 

 covered in the drawer of the stand. 



A portrait in oil of Sir W. Herschel, in one of the rooms of the same house, 

 was sold at the same time. Dr. Brabant, of Marlborough Buildings in this 

 city, who was a great friend of Sir W. Herschel, has often called on Mr. 

 Smith to see the telescope, and repeatedly declared to him that this was the 

 same instrument by which the planet Uranus had been discovered in 1781. 

 It is supposed to have been made by Sir W. Herschel, while organist in the 

 Octagon Chapel, Bath. 



1834. 10-ft. Newtonian Reflecting Telescope by Sir 

 William Herschel, with 8J inch large mirror, small plane re- 

 flecting mirror, and several eye-pieces of various powers. 



Rev. Robert Main, Director of the Radcliffe Observatory, 



Oxford. 



This telescope was made by Sir William Herschel for the Radcliffe Observa- 

 tory in the year 1812, and was received at the Observatory in April 1813 ; Sir 

 Wiliiam himself having come to Oxford to superintend the mounting and the 

 adjustments of the mirror. 



The correspondence with Dr. Robertson, who was then Radcliffe Observer, 

 is preserved at the Observatory. 



1834a. Eight plans of the Telescope, made in London at 

 the end of the last century, under the direction of Sir William 

 Herschel, for the Royal Observatory at Madrid. 



Astronomical Observatory -, Madrid. 



These plans give an exact idea of all the details of the instrument and 

 mounting. 



The speculum was of 2 feet aperture and 25 feet focal length. 



This instrument was sent from London in 1801, and set up at Madrid in 

 1804. Four years afterwards the French converted the observatory into a fort, 

 the telescope was destroyed, the only part remaining being the speculum. 



1836a. Small Hand Speculum Polishing Machine, 

 constructed and used by Sir William Herschel to polish specula of 



