GRISCOM ON METEOROLOGICAL OBSERVATIONS. $4.1 



Grounded upon views of this nature, an opinion of the importance 

 of accurate and numerous meteorological observations appears recently 

 to have prevailed in many places, especially in Great Britain. 



We are not aware of there being any complete regular series of ob- 

 servations kept in this country. We know, at least, of no journal in 

 which such a series is registered. It appears to «s* very desirable that 

 this deficiency should be supplied: and we should willingly hope that 

 an example, fairly held up by this society, would be followed by similar 

 associations in other parts of the United States. 



We proceed to an enumeration of those particulars which we consi- 

 der as the principal desiderata in observations of this nature. 



1st. Changes of temperature. 



In the choice of a thermometer, as the standard of temperature* 

 great care should be taken that the instrument be well made. The 

 diversity so frequently observable in thermometers under the same 

 exposure, arises principally from the want of a complete expulsion of 

 air from the tube, and from imperfect graduation. For the estimation 

 of sudden changes of temperature, thermometers with cylindrical reser- 

 voirs are preferable to those which are globular. 



The mean heat of the atmosphere is so easily affected by irregular 

 currents of air through halls, entries, and other situations within the walls 

 of a building, that it is deemed absolutely necessary, in order to arrive 

 at the standard temperature, that the instrument be exposed to the 

 x)pen air, sheltered only from the sun and rain. A situation which we 



J This paper was read as the report of a committee appointed to consider of the subject to 

 which it relates. 



