PLATES. 



*,* Tilt Plates are wrong numbered, hut may be distinguished 

 by observing that some are marked with Ariibic and some with Roman 

 numerals. 



Pi, ATE 1. refers to ]Mr. Airy's Paper on the Splierical Aberration 

 of Eye-pieces, No. I. 



2. refers to Mr. Airy's Paper on tlie Theory of Escapements, 

 No. III. 



I. refers to M\: Willis's Paper on the Pressure of a Stream 

 of Air upon a I'late, No. IV. 



IV. refers to Mr. Morton's Paper on the Focus of a Conic 

 Section, No. VIII. 



4. refers to Mr. Willis's Paper on Vowel Sounds, No. X. 



6. refers to IMr. Challis's Paper on the Vibrations of Elastic 



Fluids, No. XI. 



7. refers to Mr. Miller's Paper on Crystals, No. XV. 



8. No. XIX. 



9. refers to IMr. Coddington's Paper on the Microscope. 



