HE CORD AND DISCUSSION OF FORCE OF WIND. 



81 



The greatest quantity of air moved over the place during the year comes from 

 a quarter bounded by the true directions S. E. by E. and N. N. E.; the prevailing 

 wind also comes from this quarter. With the exception of true S. W. by S. winds, 

 there is comparatively hardly any wind from the remaining directions; the quad 

 rant between (true) west and north is particularly defective in this respect. 



The calms greatly predominate, there being during the year more hours of calm 

 (50G3) than hours of Avind from any direction (3697) a circumstance quite cha 

 racteristic of the locality. 



Average Duration of t7ie Winds. -The number of consecutive hours during which 

 any one wind blew is given in the table below. It contains average values made 

 out from all observations during the seventeen months. The number of consecu 

 tive hours during which, on the average, calms lasted, is likewise given. 



Magnetic direction. 



S. . . 

 S. AV. 

 AV. . 



N. AV. 



N. . 



Mean duration. 



. 3.4 

 . 2.0 



o. 4 



2.7 



Eolation of Winds. Owing to the great number of calms, and partly, also, to 

 the generally small quantity and velocity of the winds between the (true) S. and 

 (true) N. W. directions, Dove s laws of rotation cannot Avcll be verified in this 

 locality. There is, however, a tendency of the magnetic S., S. E., and E. (E. N. E., 

 N. N. E., and N. N. W., true) winds to shift, in accordance with the law, in the 

 proportion of three cases for to one case against it, or Avith a relative probability 

 of three-fourths in favor of the law. 



Note on the Occurrence of Gales. Between September 1st, 1853, and January 

 24th, 1855, there were recorded thirteen gales (with a force of 7 and aboA e, and a 

 duration of not less than two hours). The date, direction, and duration of these 

 gales is shoAvn in the following table. 



1853 



1854 



These gales do not appear to be confined to any particular season of the year. 

 On the average they last seven hours, and in summer they have a tendency to 

 blow from the S. W. (true E. S. E.), and in winter from the S. E. (true N. N. E.). 

 These two directions are the only ones from Avhich gales Avere observed. 



TTiermometric and Barometric Wind Rose. The investigation of the connection 

 of the temperature and weight of the atmosphere Avith the direction of the Avind, 

 Avill be found in the discussion of the observations for temperature and barometric 

 pressure, parts I and III of this paper. 

 11 



