29 
sources of error, the report of the Commission is not yet 
completed. 
II. 
A Committee on the Practicability and best Mean’ of Improv- 
ing the Navigation of the River and Reclaiming the Har- 
bor of San Juan del Norte, Nicaragua. 
(Appointed August 10, 1866, at the request of the Minister of the 
Republic of Nicaragua through the State Department.) 
A. A. Humpenrers, Chairman. 
(C. H. Davis. J. E. Hirearp. 
And under Art. IT., Sect. 4, 
Henry MitcHELL. 
The Committee reported to the Academy January 26. 
The report was adopted, and a copy transmitted to the Secre- 
tary of State. 
TY. 
A Commitice on the Galvanic Action from the Association 
of Zinc and Iron. 
(Appointed January 8, 1867, at the request of the Quartermaster- 
General.) 
Josern Henry, Chairman. 
J. H. C. Corriy. JosErH SAxTON. 
The Committee reported January 24,1867. The report 
Was adopted, and a copy transmitted to the Secretary of War. 
At the request of the Secretary the Committee was con- 
tinued and requested to report upon the best material for 
constructing head-blocks for marking soldiers’ graves. 
3* 
