CHAPTER XXII. 



OBSERVATIONS AT SEA. 



Flying-fish. — Their Eange — Object of their Flight —Always away from the 

 Ship — Mode of Flight — Absence of Vibration of Wings — Nature of 

 Impulse — A Flying-fish Hunt — Albicores — Abundance of Flying-fish — 

 Trichodesmium, or Sea Dust — Red Sea Conferva^Abundance of Con- 

 ferva in the China Sea — Its Range — Cases of Red Discoloration — 

 Microscopic Characters of Sea Dust — OsciUatoria — Observations of Former 

 Voyagers — Horizontal Rainbow — Development and Peculiarities — 

 Changing Aspect of the Sea — Natural Colour of the Deep Sea — Changes 

 in Shallow Water— By Rough Weather — Father Seochi's Spectroscopic 

 Observations. 



Although few animals have been more often referred to 

 than the flying-fish, and their habits described by many ob- 

 servers, the accounts concerning them are so conflicting that 

 I was anxious to arrive at an unbiassed conclusion upon 

 certain points respecting these interesting creatures, and I 

 lost no opportunity of watching their movements with that 

 end in view. I did not notice any flying-fishes on approach- 

 ing the Equator, until reaching lat. 19^° N. in the Red Sea ; 

 but we afterwards found them as high as 26° N. in the 

 Western Pacific in summer. In the Southern Hemisphere 

 we lost them in 20|° S. in the Indian Ocean, and did not 

 meet with them again tiU 14° S. in the Atlantic, (perhaps 

 because it was winter in that part of the world), and finally 

 parted with them in about 26° N. 



The statements made regarding their mode of flight by 



