176 



OBSEKVATIONS ON THE WINDS. 



what frequently in conjunction with N.W. and North, evidently in tne 

 closest connection with the decreasing northern declination of the sun. 



8. Between 55° and 74° W., in double per-centages. 



That the characteristics of summer and winter vary greatly from the 

 yearly mean is seen immediately, and at the same time the almost com- 

 plete discontinuance of the symmetry in the variation of the wind numbers 

 in winter and summer on the one hand, as compared with spring and 

 autumn on the other. Certainly the Easterly winds fall short in winter 

 but with them also the Southerly and South-Westerly, and, in their stead, 

 the powerful winds from N.W. and North prevail, which are known to 

 sailors as the dreaded snow-storms. In spring, if the sea cannot rise in 

 temperature as quickly as the flat American continent, owing to the flow 

 of ice over the Banks of Newfoundland, the N.E. to S.E. winds blow on 

 to the land ; in summer, the cool S.E. to S.W. winds prevail on the 

 American coast, blowing from the cool sea on to the land, which has been 

 raised to Italian heat, until, at length, in autumn, the cold N.W. wind 

 accompanies the sudden transition to winter. As, in summer, with the 

 increasing Northern declination of the sun, the Gulf Stream also advances 

 some degrees to the Northward, calms are not rare, owing to the greater 

 equality of temperature between land and sea. 



The task now remains to us — after having investigated the distribution 

 of the Winds, so important for general climatology, according to longitude 

 — to prove whether, for the practical purposes of navigation (and we always 

 keep in view the interests of sailing vessels as well as steamers) : — 



C. The distribution of the winds according to latitude and longitude leads 

 to results which are worth notice. 



The question now presents itself whether a ship, in any certain season 

 of the year, should keep a decidedly or partially Northern or Southern 

 course from and to America, and what she should do in any certain position 

 if overtaken by contrary wind or gale. 



We have only to deal with the general question what answer should be 

 made for the separate quarters of the year. With this object we shall 

 investigate for each longitudinal section the simple per-centages of the 

 winds to the North and South of the latitudes under consideration. li 

 the Southern zone has a less per-centage than the Northern, we shaU 

 denote the same by the sign — , and the converse by the sign +. 



