LIST OF ILLUSTRATIONS. 



Facing page 



Plate 1. John Shaw Billings, 1838-1913 7 



Plate 2. A. Cephalocereus. St. Christopher, British West Indies 58 



B. Cactus anchored in rocks on shore facing the sea, St. Christopher, 



British West Indies 58 



C. Scene from Desert Region at Azua, Dominican Republic. The large 



plant in the center represents a type of Ojmniia known only from 



the West Indies 58 



Plate 3. Figures of Leptinotarsa 68 



Plate 4. Animal House, first and second floor plans 122 



Plate 5. Pasadena Office Building, Mount Wilson Solar Observatory 195 



Plate 6. Grounds and Buildings, Pasadena, California 232 



Plate 7. Library in the Ofhce Building, Mount Wilson Solar Observatory 236 



Plates 8-12. Research Building, Department of Terrestrial Magnetism: 



8. Upper figure: Front view; building faces southwest 260 



Lower figure: Rear view; shows entrance to sub-basement 260 



9. Details of Entrance 260 



10. Upper figuie: Transverse sectional view 260 



Lower figure: Instrument shop, basement 260 



11. Upper figure: Magnetic Laboratory, first floor 260 



Lower figure: Office and Archives, second floor 260 



12. Upper figure: Sub-basement and Constant-temperature Rooms 260 



Lower figure: Half Plan of Roof and Observation Deck 260 



Plate 13. Magnetic Work of the Department of Terrestrial Magnetism, 1905-1913 . . 270 



vn 



