Januaey 18, 1907] 



SCIENCE 



115 



aecumulatiiig. Captain Tilho, of the recent 

 Anglo-Frencii Boundary Commission, points 

 out that since the explorations of Barth and 

 Nachtigal the form and area of Lake Chad 

 have been profoundly changed. Navigation 

 is only possible in certain places, and boats 

 continually run aground. Instead of the 

 great waves which, during strong winds, gave 

 the lake the appearance of an ocean, there is 

 now a tendency toward the development of a 

 vast marsh (del et Terre, November 16, 

 1906). It may be noted, in this connection, 

 that there is nothing unreasonable in the sup- 

 position that Lake Chad is undergoing a tem- 

 porary desiccation, which may again be fol- 

 lowed, after some years, by another period of 

 high water. E. DeO. Ward 



JOHI} M. BROOKE 



At his home on the outskirts of Lexington, 

 Va., on December 14, within one week of his 

 eightieth birthday. Colonel Brooke passed 

 away. 



John Mercer Brooke was born December 18, 

 1826, near Tampa, Florida. His father. Gen- 

 eral George M. Brooke, of Virginia, was a 

 distinguished officer in the war of 1812, and 

 his mother. Miss Thomas, was a native of 

 Massachusetts. At the age of a little over 

 fourteen years he became a midshipman in 

 the navy, and three years were spent in cruis- 

 ing. In 184Y he was graduated from the 

 Naval Academy at Annapolis, and soon after- 

 ward was assigned to work in the coast survey. 

 From 1851 to 1853 he was stationed at the 

 Naval Observatory in Washington, where 

 began his life-long friendship with Matthew 

 F. Maury, the distinguished hydrographer. 



For several years prior to the civil war 

 Lieutenant Brooke was engaged in making 

 hydrographic surveys in the Pacific Ocean, 

 particularly in the archipelago and along the 

 coasts of China and Japan. It was in 1854 

 that Commodore M. C. Perry induced the 

 Japanese to sign their first foreign treaty by 

 which trade was opened with the United 

 States, and good treatment was promised to 

 shipwrecked crews. Brooke was thus allowed 

 ready access to Japan, and while he was so- 

 journing in Yeddo in 1859 his ship was de- 



stroyed by a typhoon. He remained a num- 

 ber of months at Yokohama, during which he 

 did much to develop the confidence of the 

 Japanese in their foreign friends. They de- 

 cided to send an embassy to the United States 

 and invited Brooke to accompany it. So 

 highly was he esteemed that he was invited 

 by the Japanese ambassadors to help himself 

 from a large chest of native gold, but this he 

 declined. On the arrival of the embassy at 

 Washington the first request of the ambas- 

 sador was that the services rendered by Brooke 

 to Japan should be recorded in the archives 

 of the United States. 



It was during his extended hydrographic 

 work in the Pacific that Brooke thoroughly 

 tested his deep-sea sounding apparatus, the 

 invention for which probably he became best 

 known. He had previously originated it at 

 the Naval Observatory. With but few modi- 

 fications his method has continued in use to 

 the present time. It has been one of the 

 most important elements in extending our 

 knowledge of ocean depths and in rendering 

 possible the first successful ocean cables. 



Soon after Brooke's return to America the 

 country became rent by civil war. Along 

 with Maury he east his lot with the seceding 

 states, and the rest of his life was spent in 

 Virginia. As a Confederate officer he gave 

 his attention especially to naval ordnance. 

 While Parrott was experimenting at West 

 Point on the improvement of cast-iron cannon 

 by reenforcement of the breech with a 

 wrought-iron jacket, Brooke was absorbed in 

 similar experiments at Richmond and Nor- 

 folk, and the Brooke guns were conceded to 

 be the best made at the south. While Erics- 

 son was developing his Monitor at Greenpoint 

 Brooke and his associates were building the 

 first Confederate ironclad, known as the 

 Merrimac, which took part in the dramatic 

 naval engagement at Hampton Roads. He 

 remained at the head of the ordnance depart- 

 ment of the Confederate navy until this navy 

 ceased to exist. 



After the close of the war Maury and 

 Brooke became associated as professors in the 

 Virginia Military Institute at Lexington, 

 where Maury died in 1873. Brooke continued 



