ALEXANDER DALLAS BACHE. 445 



been accustomed to spend part of each summer in a tent at 

 some station of the survey on the top of a mountain, where he 

 took part in the measurement of angles and directed the move- 

 ments of field parties at other stations. The civil war brought 

 added labours upon him so that his constant presence in Wash- 

 ington was required, and his health no longer obtained the 

 yearly recuperation of this season of outdoor life. During the 

 alarm in Philadelphia which immediately preceded and followed 

 the battle of Gettysburg, the services of Mr. Bache, with a 

 corps of his assistants on the Coast Survey, were accepted by 

 the city and utilized under the direction of General N. J. T. 

 Dana, in reconnaissances and the throwing up of such earth- 

 works near the city as might frustrate a raid of cavalry. Suc- 

 cessful defence against a victorious army of the enemy would 

 have been impossible, both from the nature of the ground 

 about the city and the lack of troops to make a stand against 

 such a force. Although overburdened with other public duties, 

 Prof. Bache personally superintended the construction of some 

 of the works. Unaccustomed for many years to direct expo- 

 sure to the sun, this undertaking brought on the first indica- 

 tions of the malady that ended his life. He had been subject 

 to attacks of " sick headache " a tendency which he seems to 

 have inherited and now various symptoms of softening of the 

 brain came upon him in succession. For several months he 

 was very anxious about the business of the Coast Survey, and 

 with difficulty could be restrained from attempting to perform 

 the duties of his office. As the malady increased, however, his 

 attention was gradually withdrawn from the exterior world, 

 with which he almost ceased to hold active communication. A 

 trip to Europe, covering a period of eighteen months, produced 

 no permanent benefit. He died a short time after his return, 

 at Newport, R. I., February 17, 1867. 



The ability and worth of Dallas Bache brought him many 

 and high honours. There were few of our leading learned so- 

 cieties that did not number him among their associates. He 

 was President of the American Association for the Advance- 

 ment of Science in 1850 and 1851, of the American Philosoph- 

 ical Society in 1855 and 1856, and of the National Academy of 

 Sciences from its establishment in 1863 until his death. He 

 was a member also of the Royal Society of London, the Im- 

 perial Academy of Sciences at St. Petersburg, the Institute of 



