PROCEEDINGS OF THE SOCIETY. 429 



manner . . . leaving the stage'entirely free and open by taking away the 

 legs, applying a fine-threaded screw to regulate and adjust its motion, 

 and adding a concave speculum for objects that are opake." * The in- 

 strument thus invented by Cuff proved a very good and popular one, 

 and contrasted favourably in its simplicity and compactness with the 

 cumbersome Microscopes of the period. The model was afterwards 

 copied by Adams, Jones, Dollond, and other makers as late as 1797. 



About 1775 Dollond introduced a third bi-convex lens in the eye- 

 piece for the purpose of increasing the field of view, and as the present 

 model possesses this extra lens it is suggested by Mr. Thos. Court that 

 at some time between 1775 and 1800 the instrument was placed in 

 Dollond's hands for repairs, and the addition then made. Colour is 

 lent to this suggestion by the fact that the box foot contained a descrip- 

 tive circular by P. and I. Dollond, opticians in St. Paul's Churchyard, 

 and not the original by Cuff. All other Microscopes made by Cuff seem 

 to have only two lenses in the eye-piece. 



John Cuff appears to have been a noted optician in the eighteenth 

 century, highly esteemed by Henry Baker amongst others. Baker 

 states that in the year 1740 a gentleman from Prussia, the ingenious 

 Dr. Lieberkulm, arrived in London and showed his Microscopes, a 

 solar Microscope, and one for opaque objects, to several gentlemen of 

 the Royal Society, and also to some opticians, amongst whom Mr. Cuff, 

 " against Serjeant's Inn Gate in Fleet Street, has taken great pains to 

 improve and bring them to perfection." 



To the solar Microscope, Cuff added a rotating mirror ; and Lieber- 

 kuhn's silver speculum, perforated in the centre, he applied to the 

 compound Microscope by sliding it over the object-glass in the way 

 it has been done up to very recent times, in particular in Powell and 

 Lealand's Microscopes. 



The box contains six object-glasses, finely ground, and polished 

 single lenses, of various foci, and the usual accessories ; condensing lens, 

 frog plate, black and white discs, light modifying cone and ivory object 

 sliders, etc. 



The following particulars about Cuff have been supplied by Mr. 

 Court. In the London Gazette for November 27, 1750, Cuff's name 

 appears amongst the list of bankrupts ; he is described as a spectacle 

 maker of St. Dunstan in the West ; his sign was a Microscope, Culpeper- 

 Scarlett type, and three spectacles. The date of Cuff's death is not at 

 present known, but he was supplying meteorological information to the 

 Universal Magazine for the years 1758, when he describes himself as 

 opposite Salisbury Court, and 1759, 1760, and 1761, when his address 

 is opposite Shoe Lane ; after this such information ceases to be given, 

 and it is probable that he died about that date. 



The Society now possesses three of Cuff's new constructed double 

 Microscopes, one signed by him in Latin, another signed in English, 

 and the third made and signed by Dollond. 



On the motion of the President, a hearty vote of thanks was accorded 

 to Messrs. Rousselet and Court for their interesting communications. 



* Employment for the Microscope, 1753, p. 422. 



