238 KKCOKI) OK THE ROYAL SOCIETY 



;; H;,, _ il Tele-rope. 



(1) An Object-glass of 1:2.2 feet focal length, with an eye- 

 l ,',f (> inches, and original apparatus for adjust- 

 ment, made by Huygens, and presented by him to the 

 Royal Society in 1691. 



i The apparatus for using Huygens's object-glass, con- 12 parts. 

 strueted by Ilooke. 



(3) Additional apparatus, by Dr. Pound. Presented by Dr. 



Bradley. 



(4) Ditto, by Mr. Cavendish. 



4. An Object-^lass by Huyuens, of 170 feet focal length. Presented to the 



Royal Socict// by Sir Isaac Newton, P.R.S. 



5. An Objirt-glass by Huygens, with two eye-glasses by Scarlet, for a 



Telescope of 210 feet. Presented by the Rev. Gilbert Burned M.A., 

 F.H.S., in 1724. 



6. An Object-glass (Venetian), of 90 feet focal length : which belonged to 



Flamsteed. Presented to the Royal Society by James Hodgson, F.R.S., 

 in 1737. 



7. Chronometer, by Arnold. 



8. Chronometer, by Arnold. 



Both these Chronometers accompanied Captain Cook on his second and third 

 Voyages, 



9. Armed Loadstone. 



<;rr\v's ' Catalogue of Rarities' (p. 364) mentions an Orbicular Loadstone or Ter- 

 \r]r//<i, Driven hy Sir Christopher Wren, the size of which, so far as the stone is 

 rum-erned, agrees with the above ; it is conjectured that it may he the same. 



10. A Galvanic Battery, made by Dr. Wollaston, in a tailor's thimble. 



Presented to the Royal Society by Sir A. W. Franks, June 28, 1879. 

 In a letter to the late William Spottiswoode, P.R.S., which accompanied this 

 pn-nit. Sir (then Mr.) Augustus Wollaston Franks says that this little battery 

 was given hy his godfather. Dr. Wollaston, to his mother, then Miss Sebright. 

 iUo an anecdote about this battery in Weld's ' History of the Royal Society', 

 vol. -2, p. :'.<><). 



11. Dr. Priestley's Electrical Machine. 



1'.'. The original Model for Davy's Safety Lamp. 



\'\. The Mountain Barometer used by the late Mr. Charles Darwin, F.R.S., 

 during his voyage round the world in H.M.S. 'Beagle'. Presented by 

 ///.v c.n'cutorx in December, 1899. 



M i radiometers and otheoscopes used by Sir William Crookes to 



illustrate his papers read before the Society between 1875 and 187H in 

 connexion with his researches on 'Repulsion Resulting from Radiation'. 



titcd by Mr William Crookes, For.Sec.R.S., October, 1911. 

 The remainder of the instruments lately in the possession of the Society 

 deposited in the Science Museum, South Kensington. 



