464 Scientific Intelligence. 
SCIENTIFIC INTELLIGENCE. 
I. CHEMISTRY AND PuHysics. 
1. A Numerical Estimate of the Rigidity of the Earth; by 
G. H. Darwin, F.R.S. (Proceedings of the British Association 
for 1882.)—About fifteen years ago Sir William Thomson 
pointed out that, however it be constituted, the body of the earth 
must of necessity yield to the tidal forces due to the attraction of 
* 
the sun and moon, and he discussed the rigidity of the earth on 
number of stations by the Indian Government. The results of 
these observations are now being issued yearly by the Secretary 
of State for India in the form of tide-tables for the princi 
Indian ports. I have had the pleasure of carrying out the exam- 
ination of the tidal records, and a detailed account of the work 
will appear at $848 of the new edition of Thomson and Tait’s 
“ Natural Philosophy,” now in the press. 8 
The tides chosen for discussion were a lunar fortnightly decli- 
national tide, and the lunar monthly elliptic tide. These tides 
must be free from the meteorological disturbances which make 
the heights of all the solar tides quite beyond prediction. The: 
