REPORT OF THE SECRETARY. 17 



RESEARCHES. 



Ill the last report an account was given of an investigation of the 

 ancient solar eclipses by Mr. Todd, of the Nautical Almanac Office. 

 Among a number of eclipses added to the list then given are three ob- 

 served in China in 709 B. 0., 001 B. C, and 549 B. C, being the eclipses 

 which have formed the subject of a paper by Schjellerup, of Copenha- 

 gen. During the past year the work of this investigation has consisted 

 mainly in the collection of data and their preparation for discussion. 

 As the research progresses, there seems reason for extending the scope 

 of the research to include a large number of ancient ecliptic dates. 



Apparatus for Testing titone. — Many years ago a series of experiments 

 were conducted at the Smithsonian Institution, under the direction of 

 Professor Henry, in regard to the strength and durability of building 

 materials, primarily for the purpose of determining what varieties of 

 marble and other stones were best adapted for the construction of the 

 extension of the United States Capitol. The apparatus used in these 

 experiments has since been lying idle in the Smithsonian building, and 

 as it occupied valuable space it has been returned to the arsenal, from 

 which it was originally borrowed. It has there been put in order, and 

 is now again in use by the Ordnance Bureau of the Army. 



LABORATORY. 



As stated in the last report, after a partial suspension of active opera- 

 tions in that direction, the laboratory of the Institution was put in order, 

 and again made available for scientific research. This lias always been 

 an important feature in the operations of the Institution, and is one of 

 those especially required by the act of Congress. 



A thorough overhauling of the old instruments and equipment w; is 

 made under the direction of Dr. Endlich, the chemist in charge, and all 

 obsolete apparatus and unserviceable material was eliminated. The 

 chemical and physical departments of the colleges in the District, such 

 as the Columbian, Georgetown, and Howard University, wer j invited 

 to select from this unserviceable matter what they could use for pur- 

 poses <>f instruction, the remainder being suitably disposed of. The 

 apartments were then altered to meet the requirements of the present 

 day, and a sufficient amount of apparatus and equipment obtained to 

 make a fairly efficient working establishment. 



The work of the laboratory consists partly in determining the charac- 

 ter of various minerals belonging to collections in the National Museum, 

 and partly in carrying on researches asked for by the various depart- 

 ments of the government. No private work of this kind is undertaken 

 by the Institution; but whenever a chemical investigation of any sub- 

 ject is required by the proper authorities it is carried out, if the time of 

 the chemist will permit. 



Under the first head, the identification of large numbers of specimens, 

 previously undetermined, has been completed, the series placed in the 

 S. Mis. 54 2 



