Dr Gairdner's Observations during a Voyage, 291 



performance. A merchant vessel was not the most favourable 

 place for such observations. I regularly noted the height of the 

 barometric column at 9-10 a. m., noon, and 4-5 p. m., besides 

 different observations at shorter intervals on particular occasions. 

 You will form a better idea of these from the following Tabular 

 View, which I drew up at the conclusion of the voyage. I con- 

 fine it to the two torrid zones, as there the atmospheric pheno- 

 mena proceed with a regularity unknown in temperate latitudes. 



