;0L. LXIX.] 



PHILOSOPHICAL TRANSACTIONS. 



503 



The numerical application of the particular case of the equal lenses a and c. 



Ft. In. 



Let AD = p = 1 728 lines =12 



foB = 0.2361 F = 408 lines . 2 



^, , „, [ab = 0.5278 p = 912 lines 6 



Then we shall have ?• ^ „«o^ .-,„^i- 



flA = 0.7039 F = 1 320 Imes 9 



LoD = aB + BD= 1.7639f= 3048 lines. 21 



It is from this particular case, in which ^ =/, and /= f X (/S — 2) = 



0.23607 F, that the following table is constructed. 



O 



10 



4 



2 



1 



X/A^. On the Organs of Speech of the Orang Outang. By Peter Camper*, 

 M. D., late Professor of Anatomy, &c. in the University of Groningen, and 

 F. R. S. Jddressed to Sir J. Pringle. p. 1 39. 

 It is asserted by many travellers, that, though theorang outangdoes not speak, he 



* Dr. Peter Camper, so celebrated for his labours in comparative anatomy, was born in 1722 at 

 Leyden, where he studied the profession of physic. After taking his degree of m. d. at that uni- 

 versity, he proceeded on his travels to England, France, and CJermany ; attenLiing the lectures and 

 demonstrations of the most eminent teachers of physic, surgery, and anatomy, in each of these 

 countries. On his return from his travels he was elected professor of anatomy and surgery at Am- 

 sterdam, and was afterwards appointed to a similar professorship at Groningen, which he held with 

 increasing reputation for a great number of years. He died at tlie Hague in 1789, in the 67th year of 



