2 94 THE POPULAR SCIENCE MONTHLY 



west and northwest winds are responsible for the severity of our winter; 

 and the southwest wind for the heat of summer. Counting the actual hours 

 of flow of air in different directions, it appears that the west prevails one 

 fifth of the time, the northwest, nearly as long, and the southwest, one 

 sixth of the whole period. In a year, the west wind blows 1,739 hours, 

 the northwest 1,609 and the southwest 1,412. The total duration of all 

 winds from easterly points of the compass is but 1,950; and the ratio of 

 east to west is as four to ten. The east wind by itself prevails only six 

 hours in a hundred and so can hardly be a controlling factor of the cli- 

 mate. But some one may say : " Granting that the east wind does not 

 blow as long as the winds from other quarters, possibly it blows harder ?" 

 No, just the opposite is the case. The mean velocities in meters per 

 second from sea-level up to a mile, are NW. 12, W. 12, SW. 11, N. 11, 

 S. 10, NE. 9, SE. 9 and E. 6. This proves that the east wind is the 

 feeblest of all the winds. Moreover easterly winds blow more frequently 

 in summer than in winter. The east wind is also the current of most 

 uniform velocity, i. e., the least gusty, while our friends Boreas and 

 Skiron true to their reputations are genuine gust makers. The 

 period of greatest gustiness or instability, is the afternoon. All the 

 winds increase in velocity with elevation up to a certain height; but the 

 east and northeast winds are not deep and at an elevation of two 

 kilometers (6,562 feet) these winds rarely occur. There are two kinds 

 of east wind, the cyclonic wind which is moderately strong ; and the sea- 

 breeze which is only a few hundred feet in depth. The latter occurs on 

 clear, warm, quiet days and never when the pressure distribution is 

 favorable for turbulent conditions. It does not originate on land but 

 comes in from the sea and seems to push away slowly the quiet, stagnant 

 air in front. The ripples on the water as the breeze works its way land- 

 ward look like schools of mackerel. On very quiet warm mornings the 

 breeze may arrive as early as ten o'clock. It veers slightly as the sun 

 gets half-way down and dies away as gently as it began. It does not 

 penetrate far inland and its effect in lowering the temperature is 

 limited to a few miles back from the shore. It comes too at a season 

 when the air-gods seemingly are willing to rest, when the storm fre- 

 quency is a minimum, when the Atlantic and the land have respite 

 from the strenuous succession of storms. Then ceases for a while the 

 rapid alternation of "high" and "low," the alternation which causes 

 the characteristic changeableness for which the east wind is made 

 scapegoat. 



Truly men have much to learn about the medium in which they live, 

 the very air they breathe. Paradoxically the orchardist blames the frost, 

 as he sees it, for the damage to his crop, whereas the congealed water 

 in the process of solidifying retards the fall in temperature, giving 



