[ 108 ] 20 



observations which may have been made on the planet, and compare them 

 with the ephemeris, in order, if necessary, still further to correct the orbit. 



Meteorology. — The general system of meteorology now in operation in 

 this country, and described in the last report, has during the past year been 

 continued and gradually extended. The instruments constructed under the 

 direction of the Institution, with the aid of Professor Guyot, have been further 

 improved, and some slight changes;, indicated by experience, have been made 

 to render them more convenient to the practical observer and they may 

 now be considered not only equal in accuracy to the instruments of the best 

 construction from abroad, but in some respects superior. They are furnished 

 with the means of read " adjustment to the standard : -jtruments, and being 

 in every instance accur Ay compared before they are used, and the error 

 corrected, the labor of inserting a correction in the journal is avoided. New 

 efforts have also been made to obtain a still more accurate comparison be- 

 tween the standard barometer of this country and those of the more impor- 

 tant European observatories. For this purpose a second standard barometer 

 by Nevyman, compared with the standard of the Royal Society, and a ba- 

 rometer by Ernst, compared with the standard of the Paris observatory, 

 were ordered at the expense of the Institution. Ey a long series of com- 

 parisons between these two instruments and others at Cambridge, (Massa- 

 chusetts,) Toronto, (Canada West,) and Washington city, the object sought 

 has, it is believed, been obtained. The thermometers also, constructed by 

 Mr. Green, of New York, for the Institution, have been compared with 

 European standards, and an important step has thus been made towards 

 obtaining reliable results as to the absolute meteorological elements of the 

 different parts of this continent. 



It was stated in the last report that the regents of the university of New 

 York had made an appropriation for supplying thirty-three academies in 

 that State with instruments, and had given the establishment of the whole 

 system in charge to this Institution. The State of Massachusetts has also 

 made a similar appropriation and arrangement. During the past year the 

 instruments for this State have been constructed, and a part of the stations 

 established under the care of Professor Guyot. 



At the last meeting of the American association, a report was made, and a 

 series of resolutions adopted, (see appendix) for extending the system of obser- 

 vations with the same instruments toother parts of this continent. These 

 resolutions directed the committee to memorialize Congress for aid in ex- 

 tending the system under the direction of this Institution ; to request the 

 Secretary of the Treasury to provide for making observations at the several 

 liffht-houses to be established on the coast of California ; to ask the sur- 

 geon-general to establish new stations at important points; to memorjalize 

 the other Stales of the Union to follow the example of New York and 

 Massachusetts, and also the Canadian government to cooperate in the 

 same enterprise. 



What may be the result of the labors of the members of the committee 

 to which this duty is entrusted, it is impossible to say. They can scarcely 

 fail, however, to awaken a more general interest in the enterprise, a. id to 

 receive a favorable response to some of the requests. 



Since the date of the last report, the system particularly intended to 

 investigate the nature of American storms, immediately under the care of 

 this Institution, has been continued and improved, both in the numl er of 

 the stations, and, in some degree, in the character of the instruments. An 



