i j 4- The National Geographic Magazine 



locity of 15 miles per hour, and capa- 

 ble of imparting to a full-rigged ship 

 sailing ' ' full and by ' ' a speed of from 

 3 to 4 knots. 



THE MEXICAN BELT OF CALMS. 



From an inspection of these diagrams 

 it is evident that the " Mexican Belt of 

 Calms," as it is known among seamen, 

 is triangular in shape, the base of the 

 triangle resting on the American coast, 

 and extending from the Gulf of Cali- 

 fornia to the Gulf of Panama, the ver- 

 tex of the triangle lying far out in the 

 Pacific, its longitude roughly coinciding 

 with the meridian 125 W., near the 

 fairway of vessels bound from San 

 Francisco to the line. In latitude, the 

 position of the vertex, as well as the 

 axis of the belt, or line along which the 

 maximum frequency of calms occurs, 

 changes slightly with the season. From 

 November to April its mean position is 

 between 5 and io° N. As the summer 

 advances and the sun moves northward, 

 however, the axis of the belt likewise 

 recedes from the equator, its average 

 position for the months May-October 

 lying between io°-i5° north. The fre- 

 quency of calms increases rapidly as 

 the coast is approached. Immediately 

 under the coast, however, a diminution 

 may in some instances be noted, due to 

 the presence of the land and sea breezes, 

 and also to the fact that at certain points 

 the trade wind of the Caribbean seems 

 to reach across the Isthmus. 



A REMARKABLE CASE OF POCKETING. 



A single example — an extreme case, 

 however — will serve to illustrate the 

 delay to which a vessel may be sub- 

 jected in the endeavor to navigate this 

 dead-center of the winds. The German 

 bark Arcona sailed from Punta Arenas, 

 a point on the Isthmus somewhat to the 

 west of Panama, December 3, 1890, 

 bound for Hamburg. Upon leaving 

 port light southwesterly winds were 

 encountered, interrupted by frequent 



periods of calm, and with these the 

 bark made the best of her way, on the 

 starboard tack, to the southward. On 

 December 10, her position at the time 

 being latitude 6° N., longitude 84 W., 

 the wind still holding from the south- 

 west, the vessel went about on the op- 

 posite tack in the hope of obtaining 

 better conditions to the. westward. 

 Thirty-two days later, or on January 

 11, 1 89 1, the position was latitude 5 

 N., longitude 88° 40' W., the total dis- 

 tance made good during the 39 days 

 since leaving port amounting to but 350 

 miles. The strong northeasterly cur- 

 rent flowing in toward the Gulf of 

 Panama set the vessel as far back each 

 day as the light airs carried her for- 

 ward, and it was not until January 27, 

 55 days out, that she finally succeeded 

 in crossing the equator in longitude 96 

 west. 



In both approaching and in leaving 

 Panama, irrespective of the port from 

 which or toward which bound, a sail- 

 ing vessel must of necessity navigate a 

 greater or less width of the belt of 

 calms just described, and in estimating 

 for a given voyage the saving of time 

 effected by the use of the canal the de- 

 lay arising from this cause must not be 

 neglected. 



THE OCEAN HIGHWAYS OF SAILING 

 VESSELS 



As organized at present, the sailing 

 traffic of the world is confined to certain 

 well-beaten highways, dictated in part 

 by the physical agency of the winds and 

 in part by the demands of trade. Tak- 

 ing the English Channel and the port 

 of New York as points of departure, the 

 most frequent destinations are, to the 

 westward (by way of Cape Horn), the 

 Pacific coast ports of South, Central, 

 and North America, and, to the east- 

 ward (by way of the Cape of Good 

 Hope), the ports of South Africa, Aus- 

 tralia, and Eastern Asia. Outward- 

 bound vessels in general carry a mixed 



