Address of Sir Wm. Thomson at the Glasgow Meeting. 387 
tain Sigsbee, who followed with like fervor and resolution, and 
made further improvements in the apparatus by which he has 
done marvels of easy, quick, and sure deep-sea sounding in his 
little surveying ship Blake ; and of the admirable official spirit 
which makes such men and such doings possible in the United 
States Naval Service. I would like to tell you too of my rea- 
son for confidently expecting that American hydrography will 
soon supply the data from tidal observations, long ago aske 
of our Government in vain by a Committee of the British Asso- 
ciation, by which the amount of the earth’s elastic yielding to 
the distorting influence of the sun and moon will be measured ; 
of my strong hope that the Compass Department of the 
American Navy will repay the debt to France, England, and 
Germany so appreciatively acknowledged in their reprint of the 
works of Poisson, Airy, Archibald Smith, Evans, and the Liver- 
pool Compass Committee, by giving in return a fresh marine 
survey of terrestrial magnetism, to supply the navigator with 
data for correcting his compass without sights of sun or stars. 
an I go on to precession and nutation without a word of 
what I saw in the Great Exhibition of Philadelphia? In the 
U.S. Government part of it, Professor Hilgard showed me the 
measuring-rods of the U. S. Coast Survey, with their beautiful 
mechanical appliances for end measurement, by which the 
three great base lines of Maine, Long Island, and Georgia, were 
measured with about the same accuracy as the most accurate 
scientific measurers, whether of Europe or America, have 
attained in comparing two meter or yard measures. 
In the United States telegraphic department I saw and heard 
the Canadian department I heard “To be or not to be,...- - 
se a the rub,” through an electric telegraph wire ; but, scorn- 
a monosyllables, the electric articulation rose to higher — 
a 
a : ° : 
ao of just such another little electro-magnet as this which 
Jour. eo tease | Serres, Vou. XII, No. 71.—Nov., 1876. 
