Plan of a Meteorological Chart. t\% 



the piirpofes intended, may be felefted for the meteorolo^ 

 gical chart. 



A MEAN between the extremes of heat and cold within the 

 twenty-four hours, which I think will be befl determined by 

 the ftate of the thermometer at or before funrife, and the 

 middle of the afternoon, fhould be taken for the temperature 

 of the weather. Perhaps it would not be amifs, alfo to note 

 the firft appearance and difappearance of birds of paffage, 

 particularly the fwallow, as a criterion by which to judge of 

 the advanced ftate of the feafons. 



Explanation of the Chart. 



At the head of the chart, on the right hand fide, are to be 

 the names of the places, where the obfervations are made, 

 oppofite to their refpeftive latitudes, expreffed on the gradu- 

 ated fcale immediately below them ; from each place, a line is 

 drawn perpendicularly downwards. The large fpace on the 

 left, is for the remarks on vegetation, oppofite to the feveral 

 months in which they occur. The next column is divided 

 into months, and its fubdvifions, carried by ftraight lines 

 horizontally acrofs the chart.' In the next column the 

 mean degrees of heat, taken from Farenheit's thermome- 

 ter, are to be inferted for every ten days throughout the 

 year ; from each of which, curve lines are to be drawn, in 

 fuch a manner, as to interfefl the perpendicular lines of the 

 feveral places oppofite to thofe times refpe6lively, in the 



