28 REPORT OF THE SECRETARY. 



tion of knowledge, for the discovery of new truths, and for the diffu- 

 sion of these among men ; that the honor of the government is pledged 

 for the faithful administration of the trust in accordance with the ex- 

 pressed will of the donor, and that consequently every intelligent 

 citizen is interested in all which relates to the administration of the 

 bequest. 



8. The collection of the meteorological and physical tables prepared 

 for the Institution by Professor Guyot, has been stereotyped and the 

 first issue has been distributed to the meteorological observers and to 

 foreign institutions. It has been received by the scientific world with 

 warm acknowledgments and special commendation. The Institution 

 has not lost sight of the proposition mentioned in the Eeport for 1856, 

 to prepare other series of tables for facilitating scientific calculations, 

 and to present in a convenient form the "Constants of Nature and 

 Art." In order, however, fully to realize all the good which will 

 result from this work, it may be necessary to solicit the aid of foreign 

 institutions; and we think it probable that the co-operation of the Brit- 

 ish Association, as well as that of some of the academies on the conti- 

 nent of Europe, may be secured. 



9. Among the miscellaneous publications of the past year should be 

 mentioned a pamphlet, accompanied by a map of the solar eclipse of 

 March 15, 1858, with an account of an instrument by which the latter 

 was projected. This instrument was invented in 1842 by Rev. Thomas 

 Hill, has since been improved, and now affords a ready means of de- 

 lineating the general phases of an eclipse, as exhibited over a large 

 portion of the earth, with sufiicient accuracy for a first approximation. 

 It consequently saves much labor, and obviates, to a considerable 

 extent, the liability to larger errors in the numerical calculations. 

 The eclipse here mentioned was visible throughout Europe, Greenland, 

 and the North of Africa; also partly visible in the northern part of 

 South America and the eastern part of North America. The map exhib- 

 its the time of beginning and ending and the different phases of the 

 eclipse over the greater portion of North America in which there was 

 any probability of observations being made. Unfortunately, however, 

 the face of the sky in the United States on the day of the eclipse 

 was overcast, and few if any observations of value were obtained. The 

 projection of the map, however, illustrates the use of the ingenious 

 mechanical contrivance of Mr. Hill, and will serve to make it gene- 

 rally known to practical astronomers. 



10. A new and revised edition of "Directions for Meteorological Ob- 

 servations" has been stereotyped and distributed. To the directions 



