METEOROLOGY. 



[Tbe following notes, derived from correspondence or from observa- 

 tion and reflection, are especially intended for the meteorological ob- 

 servers of the Institution principally in the way of answering queries, 

 wliich have been frequently propounded. They may, however, be found 

 of interest to the general reader. — J. n.] 



METEOKOLO(iY OF PORTO RICO, 



Mr. Oreorge Latimer, from Pliiladelpliia, one of the correspondents of 

 the Institution, who has resided on the island of Porto liico (rich in 

 gold) since 1S34-, informs us that the northeast trade-winds prevail on 

 the island every day of the year from about o^clock in the morning 

 until sunset ; while at night there is a strong land-breeze toward the 

 ocean on -all sides of the island. The latter is stronger, however, on the 

 west end and on the north side, winch is probably owing to the greater 

 slope of the land toward the sea in these parts. 



During the rainy season, which is from the end of May to the end of 

 October, the rain falls every day on the western portions of the island 

 from 2 o'clock until sunset. This, however, is not the case on other 

 parts of the island, which is divided longitudinally by a range of mount- 

 ains 3,000 or 4,000 feet in elevation. These mountains turn up the 

 current of the trade-wind air containing vapor into the colder regions, 

 and cause its precipitation in rain on the northern slope, while on the 

 south the land often suffers from drought for more than a year without 

 interruption. On this side of the island irrigation is resorted to, and 

 for this purpose there even exists a project to tunnel the mountains to 

 conduct the water of one of the rivers from the north to the south. 



Mr. Latimer states that occasionally there is a cessation of the ordi- 

 nary trade-wind when the air becomes almost entirely calm or light 

 winds arise, which go entirely around the compass in the course of a 

 few honrs. This state of things frequently continues several d;iys, and 

 from these, as signs, Mr. Latimer has always been able to jnedict that 

 a gale is blowing at the north. After the existence of a calm of ocean 

 and air there invariably comes a heavy rolling sea from the north, so 

 heavy that vessels cannot leave the harbor of Saint John, or load in any 

 of the other ports on the northern side of the island. Also after this, 

 in the course of a few hours, or in other cases after two days, comes 



