H 
Mr. Home’s Lecture 
arrived in town the night before they were made; he very 
cheerfully gave us his assistance the moment I made the 
request. 
Sir Henry, from his practical knowledge of mathematical 
instruments, and the habit of making observations with them, 
rendered us very material assistance in the course of our ex- 
periments, and I feel myself obliged to him for remaining in 
town till they were completed. To Mr. Ramsden and my- 
self it was a particular satisfaction to have an evidence who 
had no presupposed opinion, therefore impartial ; whose know- 
ledge of the subject enabled him to form a judgment of the re- 
sults, and to correct any error we might fall into in conducting 
the experiments. This circumstance will also give to the ex- 
periments an additional claim upon the notice of this learned 
Society. 
The first experiment was made at three o’clock, at which 
were present Sir Henry Englefield, Mr. Ramsden, and 
myself. It required some time, and considerable ability, in 
which I can claim no part, to adjust the microscope, and bring 
the cornea into its field ; when this was done, the appearances 
were so different from what were expected, that we had a dif- 
ficulty in recognizing the object ; all that could be seen was 4 
curved lines, but even these were rendered confused by reflec- 
tions from the cross bars of the sash of the window. Upon throw- 
ing up the sash, the curved lines became very distinct, and that 
which appeared the inner one in the microscope, was ascer- 
tained to be the convex projecting surface of the cornea. 
This being determined, the person whose eye was the object 
of the experiment was desired to look at the corner of a chim- 
ney at the upper end of Sackville-street, a distance of 235 
