713 



of very valuable observations* made during 

 three years by the Abbe Richenet, of the con- 

 gregation of Saint Lazare, proves, that on the 

 southern coast of China, the atmospheric tides 

 display the most admirably constancy, and that 

 their period is ascertained day by day, without 

 the necessity of having recourse to the mean. I 

 shall choose the driest month (January), in 

 which there was not one day of rain, and the 

 most humid month (June), in which twenty 

 days of rain yielded 732 millimetres of water-}-. 



* These unpublished observations, of which I owe the 

 communication to the kindness of Lord Strathallan, who 

 long resided at Canton and at Manilla, were made with two 

 barometers of English construction, with a thermometer of 

 maxima of Six, and with an hygrometer of Saussure. The 

 barometric heights, in hundredths of an English inch, are not 

 corrected by the temperature. 



t Quantity of water fallen at Macao in 1814, in one hun- 

 dred and fifty-four days of rain, of which thirty-six were 

 accompanied by thunder : 7 ft 7.6 in English measure. 



