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entific societies and colleges, together with several of the learned 
associations of Europe, gave their influence and added their 
endorsement fo the request.’’* It is gratifying to know that his 
appointment to this position was first suggested by the members of 
the American Philosophical Society. 
Among the many directions in which the operations of the Coast 
Survey were now to be extended, Professor Bache very naturally in- 
cluded terrestrial magietism ; observations of the dip and the varia- 
tion of the needle and of the intensity of the earth’s magnetism 
being introduced as a part of the regular routine. He retained his 
own personal interest in these matters, and contributed from time 
to time scientific memoirs upon them to the learned bodies of which 
he was a member. 
Of the memoirs thus communicated.a few may here be men- 
tioned. At the Albany meeting of the American Association, held 
in 1856, a paper was presented by Professor Bache, in conjunction 
with J. E. Hilgard, ‘‘ On the General Distribution of Terrestrial Mag- 
netism in the United States, from Observations Made in the United 
States Coast Survey and Others.’’ At that time the number of 
magnetic stations established by the Survey amounted to one hun- 
dred and sixty, distributed, though somewhat irregularly, along the 
entire sea coast of the United States, on a great portion of which 
magnetic observations were now made for the first time. The 
object of the paper was to deduce from the Coast Survey observa- 
tions, in connection with others of recent date, the general distri- 
bution of terrestrial magnetism in the United States, as far as the 
data available will warrant the conclusions. With regard to the 
method and instruments used, only a brief notice is given. ‘In 
observing the dec/ination, the magnetic meridian has generally been 
obtained by means of collimator magnets, using Gauss and Weber’s 
transportable magnetometer; while the astronomical meridian was 
derived from the triangle sides of the Coast Survey or obtained 
by direct observations. The df has been observed with needles of 
from six to ten inches in length, made by Gambey and by Barrow. 
Two needles have generally been used, or, when only one was 
employed, it has been carefully tested and compared. The hori- 
zontal intensity has been determined in absolute measure by vibra- 
tions and deflections, according to the methods of Gauss and La- 
mont. The units of measure are those used in the British surveys. 
*“ Address in Commemoration of Alexander Dallas Bache,’’ by Benjamin Apthorp 
Gould, Proceedings Amer. Assoc, Adv. Science, Chicago meeting, 1868, Vol. xvii, p 1. 
