RAINS AND Em^^RS. 117 



cause T^liieli made it rain in Oregon now makes it rain in California. 

 As the sun returns to the north, he hrings the calm belt of Cancer 

 and the north-east trades along with him; and now, at places 

 where, six months before, the south-west winds were the prevailing 

 "winds, the north-east trades are found to blow. This is the case in 

 the latitude of California. The prevailing winds, then, instead of 

 going from a warmer to a cooler climate, as before, are going the 

 opposite way. Consequently, if, under these circumstances, they 

 have the moisture in them to make rains of, they cannot precipi- 

 tate it. Proof, if proof were wanting that the prevailing winds in 

 the latitude of California are from the westward, is obvious to all 

 Avho cross the Eocky Mountains or ascend the Sierra Madi'e. In 

 the pass south of the Great Salt Lake basin those west winds have 

 worn away the hills and polished the rock by their ceaseless abra- 

 sion and the scorning effects of the driving sand. Those who have 

 ■crossed this pass are astonished at the force of the wind and the 

 marks there exhibited of its geological agencies. Panama is in 

 the region of equatorial calms. This belt of calms travels during 

 the year, back and forth, over about 17° of latitude, coming farther 

 north in the summer, where it tarries for several months, and then 

 returning so as to reach its extreme southern latitude some time in 

 March or xlpril. Wliere these calms are it is always raining, and 

 the chart* shows that they hang over the latitude of Panama from 

 Jime to November ; consequently, fi'om June to November is the 

 rainy season at Panama. The rest of the year that place is in the 

 region of the north-east trades, which before they arrive there, 

 have to cross the mountains of the isthmus, on the cool tops of 

 which they deposit their moistm-e, and leave Panama rainless and 

 pleasant until the sun returns north with the belt of equatorial 

 calms after him. They then push the belt of north-east trades 

 farther to the north, occupy a part of the winter zone, and refresh 

 that part of the earth with summer rains. This belt of calms 

 moves over more than double of its breadth, and nearly the entire 

 motion from south to north is accomplished generally in two 

 months. May and June. Take the parallel of 4° north as an illus- 

 tration : dming these two months the entire belt of calms crosses 

 this parallel, and then leaves it in the region of the south-east 

 trades. During these two months it Avas pouring down rain on 

 that parallel. After the calm belt passes it the rains cease, and 

 the people in that latitude have no more wet weather till the fall, 



* Vide Trade-wind Chart (Maury's Wiud and Current). 



