DIRECTIONS TO THE BINDER FOR PLACING THE PLATES. 



Plate XXXVIII 



Illustrating Sir David Brewster's Paper, Description of a Double 

 Holophote Apparatus for Lighthouses, and of a Method 

 ( of Introducing the Electric and other Lights, To face page 



( Illustrating Sir David Brewster's Paper, on the Motions and 



XXXIX. \ Colours upon Films of Alcohol and Volatile Oils, and other 



( Fluids, ....... 



XL. 



XLI. 



XLII. 



XLIII | 



XLIV.J 



XLvJ 



Illustrating Mr John Allan Broun's Paper on the Diurnal Vari- 

 ation of the Magnetic Declination near the Magnetic 

 Equator, and in both Hemispheres, .... 



Illustrating Dr Ramsay H. Traquair's Paper, Description of 

 Pygopterus Greenockii (Agassiz), with Notes on the Struc- 

 tural Relations of the Genera Pygopterus, Amblypterus, and 

 Eurynotus, ....... 



635 



653 



669 



701 



