XXVI INTRODUCTION. 



one of these great storms comes near him, that he can use as 

 much wind in the borders of the storm as will suit the purposes 

 of navigation for heaven undoubtedly makes the wind blow for 

 his use, and not for his destruction, provided he becomes ac- 

 quainted with the laws which govern its motions. From the pre- 

 ceding principles, he will be able to know in what direction a great 

 storm is raging, when it is yet several hundred miles from him, 

 for the direction of the wind alone points it out. If, however, the 

 storm should be of such great length, moving side foremost, that 

 it will preclude the possibility of avoiding it, he will at least be 

 enabled to know in what direction to steer his ship, to get out of 

 the storm as soon as possible. For example, if it shall be found 

 that storms between the United States and Europe always move 

 towards the east, then it will manifestly be improper to scud with 

 the wind in the latter part of the gale, when the wind is blowing 

 from the westward, because this would be to keep in the storm as 

 long as possible. (134, 170.) The sailor also will be able to 

 know when he is out of danger ; for when a great storm has 

 passed off to the east in middle and high latitudes, and to the north 

 in low latitudes, on the north of the equator, he will know that it 

 never returns ; and therefore he will not be afraid to spread his 

 sails to the wind, before the calm of the annulus comes upon him. 

 The mariner will finally be able, by observing storm clouds on their 

 approach, to ascertain the direction in which storms move, for 

 these storm clouds frequently exhibit their front edge above the 

 horizon in the form of an arch ; and if the highest part of the 

 arch approaches towards the zenith, then is the storm coming 

 from the point where the arch first appeared. 



When a storm has a much greater diameter from north to south 

 than from east to west, the wind will not blow towards a central 

 point, but towards a central line, which may be called the trans- 

 verse diameter of the storm. 



> On the northern end of the storm, if it moves towards the east, 

 the wind will change round without a lull, by north towards the 

 west; and on the southern end of the storm the wind will change 

 round without a lull, by south towards the west ; but in the mid- 

 dle of the storm the wind will change with a lull from easterly to 

 westerly. (136, 171, et passim.) 



When the storm is of great length, north and south, the lull in 

 the central parts may be experienced simultaneously, at consider- 

 able distances apart, north and south, which could not be the case 

 if the storm was round ; and as this occurs frequently on the coast 

 of the United States, it is certain, from that circumstance alone, 

 that the centre of storms is frequently a line of great length ; and 

 moreover, as the wind in the first part of the storm is frequently 

 south east, and in the last part of the storm north west ; and as 



