56 



METEOROLOGICAL OBSERVATIONS. 



OBSERVATORY. 



ENXADOS ISLAND RIO DE JANEIRO. 



THE Observatory on Enxados Island was finished on the 7th December, when the meteorological 

 observations were begun; the following instruments being used, viz.: 



Barometer (standard). 



Attached thermometer. 



Thermometer placed in the direct rays of the sun, the bulb being covered with black wool ; one foot 

 from the ground; soil, gravel. 



Thermometer with bulb uncovered, in same situation. 



Thermometer in a well-ventilated apartment. 



Thermometer in a well two feet above the water, the well being in the cellar of the building. 



Thermometer in the water of the same well. 



Hygrometer. 



Photometer. 



The temperature of the water was observed on board U. S. Ship Vincennes. 



