ILLUSTRATIONS. 



PLATES. 



The Carnegie Frontispiece 



OPPOSITE 



PAGE 



Plate 1 . Views of Galilee, Cruise I 14 



1, Swinging ship, San Francisco, August 2, 1905. 2, Galilee under fuU sail. 3, General view of Galilee. 



Plate 2. Views of Galilee, Cruises II and III 28 



1, Observing-bridge. 2, Leaving San Diego on Cruise III. 3, Under storm staysails, en route to Callao. 

 4, Sextant observations during storm. 5, Declination observations during rough sea. 6, Inclina- 

 tion observations during rough sea. 7, Horizontal-intensity observations during rough sea. 



Plate 3. Compasses and Azimuth Devices, 1905-1908 38 



1, Ritchie standard compass. 2, Ritchie azimuth circle. 3, Ritchie compass mounted in binnacle. 

 4, Ritchie compass mounted for shore obser\'ation3. 5, Kelvin compass and azimuth mirror. 



Plate 4. Sea Dip-Circle, 1905-1908 46 



1, Sea dip-circle, Cruise I, 1905. 2, Sea dip-circle mounted on gimbal stand. 3, Modified sea dip-circle. 

 Cruises II and III. 



Plate 5. Sea Deflector, 1905-1908 64 



1, Sea deflector 1, showing observations on Cruise I. 2, Sea deflector 2, 1907-1908. 3, Standardizations 

 at Honolulu Observatory, 1907. 4, Shore tests of sight lines. 



Plate 6. Map Showing the Three Cruises of the Galilee, 1905-1908 154 



Plate 7. Construction of the Carnegie and Views of Cruise I 160 



1, State of construction. May 24, 1909. 2, Cabin and library. 3, Trial cruise, August 1909. 4, Mag- 

 netic-deeUnation observations at sea. 5, Magnetic-inclination observations at sea. 6, Launching 

 of the Carnegie, June 12, 1909. 



Plate 8. The Carnegie Under FuU Sail and the Non-Magnetic Producer-Gas Engine 170 



1, The Carnegie under full sail on her trial trip. 2, General plan of auxiliary-power plant. 3, Engine 

 room (longitudinal section). 4, Engine. 5, Engine room (cross-section). 



Plate 9. Observing Places on the Carnegie 178 



1, After observing-dome with sea deflector inside. 2, View of bridge and observing domes. 



Plate 10. General Views of the Carnegie 184 



1, Steering compass and wheel. 2, Starboard side of deck looking forward. 3, Foremast and rigging. 



4, Windlass and cables. 



Plate 11. Marine CoUimating-Compass (The Carnegie's Standard Compass) 188 



1, Compass bowl. 2, (bover cap and mounting. 3, Declination observations at sea. 4, Magnets and 

 collimating systems. 5, Compass bowl and gimbal ring. 6, Vertical section through compass. 



7, Shore observations at Colombo, Ceylon. 



Plate 12. The Carnegie's Sea Deflectors Nos. 3 and 4, 1909-1916 192 



1, Sea deflector No. 3. 2, Sea observations with No. 4. 3, Sighting device of No. 4. 4, Top view of 

 No. 4. 5, Compass bowl of No. 4. 6, Ball-bearing ring of No. 4. 7, View of compass card of No. 4. 



8, Bowl and pivot of No. 4. 9, Metal card and compass magnets of No. 4. 



Plate 13. The Carnegie's Sea Deflector No. 5, 1916 194 



1 , General view with deflecting magnet mounted. 2, View showing standards and sighting vane. 3, Top 

 view showing level and card. 4, Carrying case. 



Plate 14. The Carnegie's Inclination Instruments 202 



1, Sea dip-circle and gimbal stand. 2, Brass box and weights for loaded needle. 3, Marine earth- 

 inductor, 1912-1916. 4, Marine galvanometer. 5, Reversible gimbal stand and gearing attach- 

 ment. 



Plate 15. Views on Cruise II of the Carnegie, 1910-1913 212 



1, At Mauritius, August 1911. 2, Magnetic observations in the Indian Ocean. 3, Scientific personnel 

 and crew at Bahia, Brazil, 1913. 4, Atmospheric-electric observations. 



Plate 16. Views on Cruise III of the Carnegie, 1914 226 



1, Latitude observations at sea. 2, Shore station at Hammerfest, Norway. 3, Declination observa- 

 tions, midnight sun, Sorosund, Norway. 4, Measuring radioactive content of atmosphere. 



5, Shore station, Akranes, Iceland. 



Plate 17. Views on Cruise IV of the Carnegie, 1915-1916 254 



1, Brass and copper sheathing. 2, At Dutch Harbor, August 1915. 3, Showing propeller blades. 

 4, Standard magnetometer-inductor No. 25. 5, At Lyttelton; triangular foresail. 



Plate 18. Views on the Sub-Antarctic Voyage of the Carnegie, 1915-1916 326 



1, At King Edward Cove, South Georgia. 2, Seas encountered and showing vessel's motion. 3, One of 

 many icebergs. 4, Visitors at Lyttelton. 5, Watch officers and crew, Lyttelton, April 1916. 



6, Scientific staff, Lyttelton, April 1916. 



Plate 19. Typical Views of Shore Stations 348 



1, Freitas Beach, near Rio de Janeiro, 1910. 2, Jaburu, near Bahia, 1913. 3, Melko Island, Norway, 

 1914. 4, Sweetwater, Colon, 1915. 5, Christchurch Magnetic Observatory, 1915. 

 Pl.\te 20. Map Showing the Magnetic-Survey Work of the Department of Terrestrial Magnetism during the Period 



1905-1916 (October) 358 



Plate 21. Laboratory and Standardizing Observatory of Department of Terrestrial Magnetism 364 



Plate 22. Atmospheric-Electric Equipment for the Carnegie, 1915-1916 382 



1, Observing-house, showing covers for instruments. 2, Interior of observing-house. 3, Collecting 

 apparatus for radioactive content (outer cylinder removed). 4, Potential-gradient apparatus. 

 Plate 23. Tracks of Chief Vessels on which Magnetic Observations were made in the Atlantic Ocean, 1839-1915 .... 422 



Plate 24. Tracks of Chief Vessels on which Magnetic Observations were made in the Pacific Ocean, 1839-1916 430 



Plate 25. Tracks of Chief Vessels on which Magnetic Observations were made in the Indian Ocean, 1839-1916 438 



VI 



