ILLUSTRATIONS 



1. The Carnegie, from a water-color by William J. Peters Frontispiece 



Opposite 

 or on page 



2. Captain James Percy Ault 2 



3. The scientific staff aboard the Carnegie 3 



4. The watch-officers and the engineer 4 



5. Cruise VII of the Carnegie, May 1928 to November 1929 5 



6. Edmund Halley 6 



7. Hourly values in atmospheric-electric potential on normal day and on disturbed 



day 12 



8. Oceanographic stations. Cruise VII 15 



9. Magnetic-survey work of the Department of Terrestrial Magnetism during 



1905-1926 16 



10. Under a full spread of canvas in the Pacific 19 



11. The lofty fore-rigging 20 



12. The wooden windlass and manila hawser 22 



13. The oscillator of the sonic depth-finder 24 



14. The waist and quarter-deck viewed from the royal-yard 25 



15. Paul at the plankton-pump 29 



16. The Stevenson meteorological shelter 30 



17. Erickson, the first mate 31 



18. Parkinson testing the photographic recorder 33 



19. The case containing the delicate deep-sea reversing-thermometers 35 



20. A Richter and Wiese deep-sea reversing-thermometer 37 



21. Weighing the hydrogen-filled balloon 39 



22. Torreson observing a pilot-balloon 41 



23. A silk-net coming up after being towed from the ship 43 



24. Seiwell at work in the chemical laboratory 45 



25. The Wenner salinity -bridge 47 



26. The fore-rigging 49 



27. Looking down on the bow from aloft 51 



28. Using a marine collimating-compass 53 



29. Parkinson making a "dust-count" 55 



30. The waist as seen from the royal-yard 57 



31. The radio receiver 59 



32. Captin Ault and his family 62 



33. Dr. John C. Merriam, President of the Carnegie Institution of Washington, 



bidding good-bye to Captin Ault 63 



34. Scientific staff waving good-bye 65 



35. The Carnegie being towed out into the Potomac 67 



36. Some members of the laboratory staff 69 



37. Scott at the "deflector" 71 



ix 



