160 



METEOROLOGICAL OBSERVATIONS. 



OBSERVATORY. 



SAN LORENZO, 



INSTRUMENTS USED ON SHORE. 



Standard barometer. 



Thermometer attached. 



Thermometer, the bulb covered with black wool, hanging one and a half feet from a sandy soil, with a 

 north-and-south exposure. 



Thermometer, the bulb uncovered, in the same situation. 



Thermometer in the shade. 



Thermometer in a hole two and a half feet below the surface. 



Photometer. This instrument was exposed day and night ; at sunrise and sunset it stood at from 20 

 to 25. 



The temperature of water and at mast-head were observed on board the U. S. Ship Vincennes. 



