1884.] 56 [Carson. 



1839 ; as Assistant in the Topographical Bareau at Wasliington, D. C, 

 1840-'41 ; in the Florida war, 1842 ; on construction of bridge 'at Wash- 

 ington, D. C, 1843; as Assistant in Topographical Bureau at Washing- 

 ton, D. C, 1842-'43-'44 ; as Assistant in charge of the Coast Survey 

 Office at Washington, D. C, 1844-'49, and on sarvej'S in the field, 

 1849-'50. 



lie was engaged in making a Topographic and Hydrographic survey 

 of the Delta of the Mississippi river, with a view to its protection from in- 

 undation, and deepening the channels at its mouth, 1850-'51, continuing 

 in general charge of the work and preparing his able and voluminous 

 report thereon, till 1861. In 1853 he was sent on special duty to Europe 

 to examine means for the protection of delta rivers from inundation. He 

 was in general charge, under the War Department, of the ofiice duties at 

 Washington, D. C, connected with the explorations and surveys for rail- 

 roads from the Mississippi river to the Pacific ocean, and geographical 

 explorations west of the Mississippi river, from 1854 to 1861, and was a 

 member of the Lighthouse Board, from 1856 to 1863 ; of the Board "to 

 revise programme of instruction at the United States Military Academy," 

 and of the Commission created by act of Congress "to examine into the 

 organization, system of discipline, and course of instruction at the United 

 States Military Academj^ I860."* 



It would be difficult to overestimate the value .-^nd extent of the labors 

 of General Humphreys in the field of science. I can dwell only upon his 

 greatest work : The Report upon the Physics and Hydraulics of the Missis- 

 sippi River ; upon the Protection of the Alluvial Region against Overflow ; 

 and upon the Deepening of the Mouths ; Based upon Surveys and Investiga- 

 tions, made under the Acts of Congress directing the Topographical and 

 Hydrographical Survey of the Delta of the Mississippi River, with such 

 Investigations as might lead to determine the most Practicable Plan for 

 Securing it from Inundation, and the hest mode of Deepening the Channels 

 at the Moutlis of the Iiicer.\ 



The title but feebly suggests the vast scope of the work. 



The Mississippi river, below the mouth of the Missouri, changes its 

 character from a gentle current and a clear tide to a turbid, boiling tor- 

 rent, tremendous in volume and force. Thenceforth, for thirteen hundred 

 miles, it pursues a devious course, washing away banks and islands here, 

 rebuilding them there, absorbing tributary after tributary, until at last it 

 is itself swallowed up in the greater volume of the Gulf Just above 

 the mouth of the Ohio begins a great alluvial plain, some fifty miles in 



* statement of Services of Brigadier-General Andrew A. Humphreys, Corps 

 of Engineers, Brevet Major-General U. S. A. General Orders, No. 10, Headquar- 

 ters Corps of Engineers. U. S. A., Washington, D. C, December 29, 1SS3. 



t Submitted to the Bureau of Topographical Engineers, War Department, 

 1861. Prepared by Captain A. A. Humphreys and Lieutenant II. E. Abbot, 

 Corps of Topographical Engineers, United States Army. Philadelphia: -T. B. 

 Lippincott & Co. 1861. 4to, pp. 456: with an Ajjpendix, pp. 116, and 20 plates. 

 Reprinted, with Additions, in lb76. 



