dangerous semicircle, denoted by D, is on the inner side. of the curved track. From the foregoing conclusions rules have been drawn up for the use of navigators to enable them to determine on which tack a ship should be laid-to when confronted with a storm of cyclonic character, the object of these rules being to prevent the wind veering by the ship's head and to insure its veering or shifting constantly farther aft so that she may be constantly "coming up" to the wind, whereas in the former case she would be "breaking off" from the wind, and, even with sails set, would, in so violent a gale, be in danger of gathering sternboard. SUGGESTIONS FOR THE HANDLING OF SHIPS IN OR NEAR CYCLONES 44. As to the handling of ships in or near a cyclone the student should bear in mind that the safety of his vessel will depend to a great extent on his good judgment as well as on his knowledge of the nature and peculiarities of revolving storms. All positive rules are, of course, more or less defective, and if blindly carried out may prove very dangerous; they are, nevertheless, of great value when judiciously used in combination with a good judgment of prevailing circum stances. The first thing for a navigator to do when he has good reason to believe that a hurricane is approaching is to find the bearing of its center, and then to shape his course so as to avoid it. 45. Signs of an Approaching Cyclone.-To begin with, let us look into the matter when "There is good reason to believe a hurricane is approaching." The best general information on this subject is, undoubtedly, that given by the United States Hydrographic Office and printed on charts. that embrace cyclone-infested regions, particularly the chart of the North Atlantic Ocean dealing with West Indian hurriPart of these notes are reproduced here and should be carefully studied and remembered. canes. 46. Earliest Indications. Barometer above the normal, with cool, very clear, pleasant weather; a long, low ocean swell from the direction of the distant storm; light, feathery, cirrus clouds, radiating from a point on the horizon where a whitish arc indicates the bearing of the center. 47. Unmistakable Signs.-Falling barometer; halos about the sun and moon; increasing ocean swell; hot, moist weather with light, variable winds; deep-red and violet tints at dawn and sunset; a heavy mountainous cloud bank on the distant horizon; barometer falling rapidly, with passing rain squalls. If from the cloud bank shreds of cloud are seen projected forwards and upwards, as if by some violent ascensional movement of air, the storm center is dangerously near. 48. Warning by Reversal of Wind.-But, perhaps, the most timely and trusty indication of a cyclone is often the rise of the thermometer in connection with a reversal of the normal wind. Thus, in the regions of the trade winds a brisk westerly wind suddenly springing up should at once arouse suspicion, particularly in the hurricane season. Equally suspicious is a strong easterly wind suddenly succeeding the normal westerly winds prevailing between 40° and 45° N on the routes between United States and Europe. Scarcely anything, except an approaching area of low atmospheric pressure, can be supposed to cause the sudden change of the East Indian monsoon in August and September. A cautious navigator, therefore, may, by attending to the abnormal and sudden change of wind direction, forsee that he is in front of a revolving gale, though his barometer remains high, the sea smooth, and none of the usual signs of hurricanes can be distinguished overhead. 49. To Find the Bearing of the Center.-Being convinced that the approaching storm is of a cyclonic character, the bearing of its center is determined. This is done by facing the wind, in which position the center may be assumed to bear 10 or 11 points to the observer's right in northern latitudes and 10 or 11 points to the left in southern latitudes. If, however, the ship is well within the storm area, and the barometer is falling steadily, the bearing of the center may be less than 10 points; and if the barometer has fallen as much as inch, the bearing may be considered as 8 points. 50. To Determine Position of Ship in Relation to Storm Track.-Having the approximate bearing of the storm center the next thing to do is to find the position of the ship in relation to the track, or line of progression, of the storm. This can be determined by observing the shifting, or veering, of the wind. In the northern hemisphere, if the wind shifts to the right, the ship is to the right of the track, as at S, Fig. 13 (x), or in the dangerous semicircle; if it shifts to the left, the ship is to the left of the track, as at S1, Fig. 13 (x), or in the navigable semicircle. These conditions are reversed in the southern hemisphere. There, if the wind shifts to the right, the ship is to the right of the track, as at S,, Fig. 13 (y), or in the navigable semicircle; while, if the wind shifts to the left, the ship is at S, Fig. 13 (y), or in the dangerous semicircle (in both cases the observer is assumed to be looking in the direction toward which the storm is advancing). But if the wind is "steady," shifting but very slightly and increasing in velocity, it indicates that the ship, whether in the north or south hemisphere, is on the track and in front of the center, as at S1, Fig. 13 (x) and (y). 51. To Find Whether Center is Approaching or Receding. When a ship is well within the area of a hurricane the approach of the center is indicated by a rapidly falling barometer, increase of wind, heavy squalls, intense lightning and rain, heavy and confused sea, continued shifting of the wind, except when on the track of the center. The receding of the center is usually indicated by a rising barometer, more steady wind decreasing in velocity, weather clearing but sea very confused and dangerous. 52. Brief Rules for Action to Avoid Center.-Having determined the bearing of the storm center and the position of the ship in reference to the progressive motion of the storm, according to instructions in preceding articles, the following rules for avoiding the storm center should be adhered to as far as circumstances will permit: Rules for the Northern Hemisphere.-If on the track of the storm center and in front of the advancing storm, run or steam before the wind; keep a steady course until the wind shifts well on starboard quarter. Then, if obliged to lie-to, do so on the port tack. If in the dangerous semicircle, steam or run off with the wind on starboard quarter; if obliged to lie-to, do so on the starboard tack. If in the navigable semicircle, steam or run off with the wind on starboard quarter; if obliged to lie-to, do so on the port tack. Rules for the Southern Hemisphere.-If directly in front of the advancing storm center, run or steam before the wind; keep a steady course until the wind gradually shifts around to the port quarter. Then, if obliged to lie-to, do so on the starboard tack. If in the dangerous semicircle, steam or run off with the wind on the port quarter; if obliged to lie-to, do so on the starboard tack. If in the navigable semicircle, steam or run off with the wind on the port quarter; if obliged to lie-to, do so on the port tack. Vessels, especially steamships, sometimes overtake hurricanes because their speed is greater than the progression of the storm center. In such cases it is obvious that the ship's course should be altered so as not to approach the center. 53. The Storm Center.-The foregoing rules apply to cases when hurricanes are encountered in open sea. If, however, the vessel is unable, from want of sea room, to perform the necessary maneuvers, her position becomes one of great danger. Every precaution should then be taken to prepare for the passage of the storm center over the ship. In entering the center, which may be several miles in diameter, the wind suddenly ceases and glimpses of clear sky can be seen, now and then interrupted by puffy squalls. The sea is enormous and very dangerous, apparently coming from all directions of the compass. After the center has passed over, the ship is again struck by a gale of renewed energy and hurricane force, but from the opposite direction. This constitutes one of the most critical dangers known to seamen. Apparently, the best thing to do when caught in the center of a hurricane is to try to get the vessel in such a position as to best meet the opposite wind, which may be expected to burst forth very quickly and violently, and thereby prevent the ship gathering sternboard, or drifting backwards in a helpless position with enormous seas breaking over her. Only strongly built vessels are able to withstand the heavy strain they are subjected to under such circumstances, and many ships whose names now figure on the list of "missing" in all probability met their fate in the center of a revolving storm. 54. The typhoon of the Western Pacific Ocean is in many respects the counterpart of the West Indian hurricane of the Atlantic. Both classes of storms have their origin in the vicinity of tropical groups of islands, and under similar barometric conditions; both undergo the same slow development and exhibit a similar tendency to recurve on reaching the higher latitudes. The first barometric indication of the approach of a typhoon is the disturbance of the daily fluctuations of the mercurial column. In the low latitudes where typhoons originate, a good mercurial barometer, during settled weather should show a decided maximum about 10 A. M., the reading at that hour standing between 29.85 and 29.95 inches (758.2 to 760.7 millimeters), while about 4 P. M. there should be a corresponding minimum, the reading at that hour being about 16 inch (2.5 millimeters) less than at 10 A. M. The same thing is repeated at 10 P. M. and at 4 A. M. If the forenoon maximum is appreciably below 29.85 inches, or if the descent between this and the afternoon minimum is markedly greater than 5 inch, the weather should be watched with great care. Several successive days of light, variable winds and calms; a period of hot, sultry weather; increasing |