468 
CHARLES OTIS BOUTELLE. 
sistant in the Survey, and from that time forward gained 
steadily in standing on the work, being intrusted with the 
charge of important operations, which he conducted with his 
accustomed energy and with the professional skill and fer¬ 
tility of resource always at his command. 
For some years he carried on the reconnoissance for the 
primary triangulation upon the coast of Maine. He made 
the reconnoissance and selection of sites for three primary 
base-lines, and had personal charge of the measurement of 
a primary base-line (the Atlanta base) in Georgia. This 
measurement was three times repeated as a test of accuracy, 
the line being measured twice in winter and once in sum¬ 
mer, with an accordance of results so close that the greatest 
divergence did not exceed a millionth part of the whole 
length of nearly six miles. He conducted the primary tri¬ 
angulation which was carried from the Atlanta base north¬ 
ward and northwestward along the Blue Ridge to connect 
with the primary triangulation which was advancing south¬ 
ward and southwestward from the Kent Island base, and 
had charge of the surveys upon the coasts of South Carolina 
and Georgia. 
During this period the bent of his mind was shown by the 
improvements he introduced into the methods and processes 
of the work; among these may be mentioned the form of 
preliminary base apparatus described in the Coast Survey 
Report for 1855; his form of tripod and scaffold observing 
signal, 1855; his experiments with lights for geodetic night 
signals, carried on for several years, and brought to a suc¬ 
cessful termination in 1880 by the adoption of the mag¬ 
nesium lights and the student-lamp reflectors. 
In 1884 the charge of the Coast and Geodetic Survey office 
was assigned to him, and after his relief from that duty he 
was placed in immediate supervision of geodetic operations 
in the States which had organized their own geological and 
topographical surveys. 
For a number of years he was a member of the board of 
commissioners for the improvement of the harbor of Norfolk. 
