And here a remarkable circumstance attracts our notice, the consideration of which points to the mode in which cyclones may be conceived to be generated. It is found, by a careful study of different observations made upon the same storm, that cyclones in the northern hemisphere _invariably_ sweep round the onward travelling vortex of disturbance in _one_ direction, and southern cyclones in the contrary direction. If we place a watch, face upwards, upon one of the northern cyclone regions in a Mercator’s chart, then the motion of the hands is _contrary_ to the direction in which the cyclone whirls; when the watch is shifted to a southern cyclone region, the motion of the hands is in the same direction as the cyclone motion. This peculiarity is converted into the following rule-of-thumb for sailors who encounter a cyclone, and seek to escape from the region of fiercest storm:—_Facing the wind, the centre or vortex of the storm lies to the right in the northern, to the left in the southern hemisphere_. Safety lies in flying from the centre in every case save one—that is, when the sailor lies in the direct track of the advancing vortex. In this case, to fly from the centre would be to keep in the storm-track; the proper course for the sailor when thus situated is to steer for the calmer side of the storm-track. This is always the outside of the ⊃, as will appear from a moment’s consideration of the spiral curve traced out by a cyclone. Thus, if the seaman _scud before the wind_—in all other cases a dangerous expedient in a cyclone[13]—he will probably escape unscathed. There is, however, this danger, that the storm-track may extend to or even slightly overlap the land, in which case scudding before the gale would bring the ship upon a lee-shore. And in this way many gallant ships have, doubtless, suffered wreck. The danger of the sailor is obviously greater, however, when he is overtaken by the storm on the inner side of the storm-⊂. Here he has to encounter the double force of the cyclonic whirl and of the advancing storm-system, instead of the difference of the two motions, as on the outer side of the storm-track. His chance of escape will depend on his distance from the central path of the cyclone. If near to this, it is equally dangerous for him to attempt to scud to the safer side of the track, or to beat against the wind by the shorter course, which would lead him out of the storm-⊂ on its inner side. It has been shown by Colonel Sir W. Reid that this is the quarter in which vessels have been most frequently lost.