132 BOARD OF AGRICULTURE, 



the colder winds of the Indian Ocean come in to take the place of 

 the heated currents ; and thus a wind prevails from the month of 

 October to the month of April from the northeast. Thus we have 

 the monsoons — a northeast wind prevailing- during- one-half of the 

 year, and a southwest wind during the other half of the year. 

 The continent of Australia and Arabia are two opposing merses of 

 land which determine also the direction of currents of air ; so there 

 is a wind which prevails during one-half of the year toward Aus- 

 tralia, and during the other half toward Arabia. But the princi- ^ 

 pal winds of the Indian Ocean are the two first noticed — the south- 

 west and northeast monsoons. 



As the heated currents of air rise in the region of the equator 

 and fall back toward the poles, they come down to the earth in 

 latitude about 30"^ north and south; and here is a banking- up of 

 winds which gives rise to what are termed "the calms of Cancer" 

 and " the calms of Capricorn." As the return wind escapes from 

 this belt in the nortliern hemisphere, it blows vn a direction oppo- 

 site to that of the trade wind ; that is, it is a southwest wind, and 

 prevails between latitude 30° and 60°. So the prevailing wind in 

 the northern hemisphere, over the ocean, between latitudes 80° 

 and 60°, is the southwest return trade. In the southern hemis- 

 phere, the prevailing wind is in like manner in a direction opposite 

 to the trade wind in that hemisphere ; that is, it is a southwest 

 wind, and prevails between latitudes 30° and 60°, and is known as 

 the southwest return trade. 



These belts of wind, ranging from 30° to 60° north or south of 

 the equator, are subject to great variations, from being affected by 

 continents, mountains, chains of liills, and many other causes 

 which come in to modify their course ; so that they are known 

 upon the land as variable winds, although they are quite con- 

 stant iipon the ocean. These are the winds which prevail in our 

 own State. They are known as the " variable winds " of the mid 

 latitudes. 



The direction of the wind at the Agricultural College at Orono, 

 last year, was — from the northwest and west, 41 per cent. ; south- 

 west and south, 29 per cent. ; southeast and east, 14 per cent. ; 

 northeast and north, 16 per cent. ; verj' variable, as you perceive, 

 and unlike those iii tropical regions, which prevail in the same 

 direction throughout the entire year. 



Now, what ciTect have these winds upon the production of 

 moisture ? Allow me to take an illustration from the western 



