xvi INTRODUCTION TO THE SIXTH EDITION. 



A separate chapter is now devoted to the Land and Sea Breezes, 

 and extensive contributions have been made to that on Monsoons, 

 Trade Winds, and Cyclones. Lieutenant Jansen, of the Dutch 

 Navy, has helped me to enrich these with his fine thoughts. The 

 reader will, I am sure, feel, as I do, deeply indebted to him for so 

 much instructive matter, set forth in his very delightful and pleas- 

 ing manner. 



National Observatory, Washington, April, 1856. 



